en: Interatomic potentials remain a critical bottleneck for accurate large-scale atomistic simulations. Machine-learning potentials provide a promising route to overcoming this limitation; however, the construction of property-relevant training datasets remains a major challenge. Here, we propose an active-learning strategy based on property balancing, in which the fraction of atomic environments associated with pre-identified key material properties is dynamically optimized during training. We demonstrate this strategy for pure magnesium, whose macroscopic plastic deformation is governed by several subtle dislocation transformations that place stringent demands on potential accuracy. Using the proposed strategy, we develop a Behler–Parrinello-type neural-network potential that captures these dislocation-mediated mechanisms with a level of accuracy that has been difficult to achieve in previous studies of magnesium. The successful application to magnesium highlights the versatility and effectiveness of property balancing as a general strategy for developing machine-learning potentials for metallic systems with multiple competing property requirements. This approach provides a practical pathway toward predictive mechanistic simulations of structural metals.

en: Property-balancing active learning strategy for machine learning interatomic potentials: case study on dislocation mechanics in magnesium

dislocation

display_name: dislocation

magnesium

display_name: magnesium

neural-network-potential

display_name: neural-network-potential


$oid: OBSOLETE

en: This dataset provides the computational data supporting the manuscript entitled "Molybdenum Oxidation State Governs Brønsted–Lewis Acid Synergy in Dimethyl Oxalate Transesterification" by Li et al., providing all computational data underlying the reported adsorption behaviors on MoO3(010) and MoO2(011) surfaces. It includes optimized bulk and surface structures, representative CP2K input/output files, and post-processed electron density data, enabling reproducibility of the adsorption energies and electron density difference maps for dimethyl oxalate (DMO) and ethanol. The calculations reveal that DMO adsorbs more strongly on MoO3(010) (−0.9 eV) than on MoO2(011) (−0.7 eV), reflecting more facile Lewis acid activation by the Mo6+-dominated surface. Electron density accumulates between the surface Mo and the carbonyl O atom, while the carbonyl C loses density, indicating polarization of the molecule upon adsorption. Ethanol adsorption shows even more pronounced differences: on MoO3(010), it interacts either with a surface Lewis acidic Mo atom or a Brønsted acidic Mo–OH site, both configurations exhibiting similar adsorption energies of approximately −1.1 eV. Adsorption on the Lewis acid site induces electron accumulation at the Mo–O bond and activation of the hydroxyl H, whereas adsorption on the Brønsted acid site increases the overall electronegativity of ethanol, enhancing its nucleophilicity. In contrast, ethanol binds weakly (−0.1 eV) to MoO2(011) via a hydrogen bond with a surface O atom, with negligible interaction with Mo sites. All data are organized in a comprehensive folder structure covering bulk crystal models, isolated molecules, surface optimizations, and adsorption energy evaluations, with hydroxylated and non-hydroxylated MoO3 surfaces included. Computational settings employ CP2K (GPW) with PBEsol for structural optimizations and BEEF-vdW for energy calculations, along with specified basis sets, k-point sampling, and slab models. The dataset enables verification of all figures and tables in the manuscript and facilitates detailed analysis of Brønsted–Lewis acid synergy in MoOx-catalyzed transesterification.

materialscloud

approval_status: approved

en:
Materials Cloud is a platform built to enable the seamless sharing and dissemination of resources in computational materials science, offering educational, research, and archiving tools; simulation software and services; and curated and raw data. These underpin published results and empower data-based discovery, compliant with data management plans and the FAIR principles.

In the Materials Cloud you can browse, explore, download, or deposit raw and curated data (in the Discover, Explore, and Archive sections); you can access cloud or redeployable simulation services (from AiiDAlab turnkey simulations to the Quantum Mobile virtual machine, the AiiDA registry of plugins and workflows, and the OSSCAR notebooks, in the Work section), and you can use all our educational material, tutorials and lectures (in the Learn section).

en: Materials Cloud

de: Materials Cloud

fr: Materials Cloud

it: Materials Cloud

political_level: other

state: active

type: organization

psi

capacity: public

en: Data for the adsorption properties of dimethyl oxalate and ethanol on the MoO3(010) and MoO2(011) surfaces

type: dataset

key: guid

key: uri

value: DCAT Harvester Materials Cloud

envi

de: Umwelt

en: Environment

fr: Environnement

it: Ambiente

adsorption

display_name: adsorption

dimethyl-oxalate

display_name: dimethyl-oxalate

electron-density-difference

display_name: electron-density-difference

moox

display_name: moox


en: Functionalizing Silicon Nanowires (SiNWs) through covalent attachment of organic molecules offers diverse advantages, including surface passivation, introduction of new functionalities, and enhanced material performance in applications like electronic devices and biosensors. Given the wide range of available functional molecules, systematic large-scale screening is crucial. Therefore, we developed an automated computational workflow using Python scripts in conjunction with the AiiDa framework to explore structural configurations of functional molecules adsorbed onto silicon surfaces. This workflow generates multiple adhesion configurations corresponding to different binding orientations using surface and functional molecule structures as inputs. This dataset contains data related to the structural optimization of molecules with single, double, and triple carbon-carbon bonds attached to the nanowire surface in various adhesion configurations. We describe the chemisorption on SiNWs using the slab models for the Si facets since our reference are samples with diameters of SiNWs around 50 nm, while the quantum confinement effects are important for diameters below 10 nm. For each configuration, structural characterization was conducted by calculating quantities including the bond distance between the two carbons closest to the surface and their respective bond angle relative to the z-axis, the carbon-silicon bond distance and its respective bond angle relative to the z-axis, along with the molecule's rotation angle in the xy plane. The values obtained are summarized in the main folder. The version v1 of dataset contains data related to the Si(111) surface and alkanes, alkenes, and alkynes with lengths from C2 to C10. The version v2 and v3 include also the moieties from C12 to C18. The version v4 extends the dataset with the data related to the Si(110) surface and alkanes, alkenes, and alkynes with lengths from C2 to C18. The version v5 also includes the optimized structures of SiNWs oriented along ⟨112⟩, exposing Si(110) and Si(111) facets, and featuring three different sizes: small (d = 0.7 nm), medium (d = 1.7 nm), and large (d = 2.6 nm). In this version (v6) the relaxation calculations for all the considered moieties are provided. For each system the most stable configuration is identified, and the analysis of the electronic properties is conducted in the listed references.

en: Density functional theory study of silicon nanowire surfaces functionalized by grafting organic molecules

aliphatic-molecules

display_name: aliphatic-molecules

dft

display_name: dft

nanowires

display_name: nanowires

silicon

display_name: silicon

surface-adsorption

display_name: surface-adsorption


en:
Semilocal density functionals such as the Perdew-Burke-Ernzerhof (PBE) functional notoriously underestimate experimental band gaps. Hybrid functionals address this “band gap problem” by admixing a fraction of Fock exchange to semilocal exchange. The optimal mixing parameter depends on the specific material and can be identified as the inverse dielectric constant (dielectric-dependent hybrid functional, DDH). Here, we show that dielectric constants obtained using the r²SCAN meta-GGA functional are significantly more accurate than dielectric constants obtained using the semilocal PBE functional. We propose the DD-r²SCANH functional, a dielectric-dependent hybrid functional based on r²SCAN. DD-r²SCANH can outperform the standard PBE-based DDH in terms of band gaps and other electronic structure properties. Particularly impressive improvements are obtained for narrow-gap semiconductors such as Ge and InAs, where PBE wrongly predicts a metallic phase, but r²SCAN opens a band gap.

Here, we provide VASP input files for DD-r²SCANH, and further we provide the crystal structures used for our band gap benchmark in POSCAR format.

en: Dielectric-dependent hybrid functional from meta-GGA

density-functional-theory

display_name: density-functional-theory

electronic-bands

display_name: electronic-bands

electronic-structure

display_name: electronic-structure


en:
This dataset supports a computational study of finite-concentration pair breaking in Mn- and Co-doped 2H-NbSe2 using the coherent potential approximation combined with Bogoliubov-de Gennes calculations within the KKR Green-function framework. The work investigates how magnetic impurities located on the van der Waals empty-sphere site modify the superconducting anomalous density of 2H-NbSe2 from the dilute impurity limit up to the critical concentration where superconductivity collapses.

The dataset contains the full AiiDA provenance needed to reproduce the calculations reported in the companion manuscript. It includes the pristine superconducting 2H-NbSe2 reference calculation, normal-state CPA KKR calculations for Mn and Co impurities, and self-consistent CPA-BdG concentration series for both dopants. These data reproduce the concentration-dependent normalized anomalous density, the impurity-dependent critical concentrations, and the comparison between Mn- and Co-induced changes in the superconducting response.

All calculations were performed with the JuKKR Green-function code through the AiiDA-KKR workflow infrastructure on the JURECA-DC supercomputer at Forschungszentrum Jülich, with additional computational resources from CLAIX at RWTH Aachen University. The record is intended to provide transparent access to the computational provenance, input and output data, and analysis workflow underlying the reported CPA-BdG results.

en: CPA-BdG calculations for Mn- and Co-doped 2H-NbSe2: finite-concentration pair breaking and anomalous density

aiida

display_name: aiida

anomalous-density

display_name: anomalous-density

bogoliubov-de-gennes-bdg

display_name: bogoliubov-de-gennes-bdg

co

display_name: co

coherent-potential-approximation-cpa

display_name: coherent-potential-approximation-cpa

kkr-green-function-method

display_name: kkr-green-function-method

magnetic-impurities

display_name: magnetic-impurities

mn

display_name: mn

pair-breaking

display_name: pair-breaking

spin-orbit-coupling

display_name: spin-orbit-coupling

superconductivity

display_name: superconductivity

transition-metal-dichalcogenide

display_name: transition-metal-dichalcogenide

yu-shiba-rusinov-states

display_name: yu-shiba-rusinov-states


en: Topological constraints such as the Bernal-Fowler ice rules govern atomic arrangements in proton-disordered crystals. Machine learning force fields (MLFFs) provide a computationally efficient route to exploring such disordered energy landscapes using on-the-fly sampling without explicit topological supervision. Whether such a data-driven approach can autonomously recover ice-rule constraints remains an open question. Here, we show that a data-efficient GAP-SOAP force field trained on 212 DFT calculations achieves a energy RMSE of 19 meV/H2O on Ice VII configurations and reproduces phonon dispersions and infrared spectra in good agreement with DFT. A representative trained model relaxes 8 × 8 × 8 supercells (3072 atoms) with randomized proton orientations into structures consistent with ice-rule constraints, recovering a body-centred cubic oxygen lattice at 30 GPa. Under compression, the model captures the qualitative features of the Ice VII → Ice X transformation and remains stable over the 30–90 GPa range for the tested configurations. While extended training does not guarantee monotonic improvement in all properties, the model enables efficient large-scale molecular dynamics, reaching approximately one frame per second on a single CPU core. These results demonstrate that local environment descriptors can encode key aspects of hydrogen-bond topology, providing a data-efficient route to structural relaxation in disordered molecular crystals.

en: Emergence of Bernal-Fowler ice rules in crystal structure prediction via data-efficient machine learning force fields: the case of Ice VII

active-learning

display_name: active-learning

crystal-structure-prediction

display_name: crystal-structure-prediction

high-pressure-ice

display_name: high-pressure-ice

ice-rules

display_name: ice-rules

ice-vii

display_name: ice-vii

machine-learning-force-fields

display_name: machine-learning-force-fields


en: Generative artificial-intelligence (AI) models, such as score-based diffusion models, have recently advanced the field of computational materials science by enabling the generation of new materials with desired properties. In addition, these models could also be leveraged to reconstruct crystal structures for which partial information is available. One relevant example is the reliable determination of atomic positions occupied by hydrogen atoms in hydrogen-containing crystalline materials. While crucial to the analysis and prediction of many materials properties, the identification of hydrogen positions via X-ray scattering experiments has been historically challenging, and often requires more expensive neutron scattering measurements. As a consequence, and despite experimental advances which enable us nowadays to accurately determine hydrogen positions based on X-ray scattering experiments, inorganic crystallographic databases still report many lattice structures where hydrogen atoms have been either omitted or inserted with heuristics or by chemical intuition. Here, we combine diffusion models from the field of materials science with techniques originally developed in computer vision for image inpainting. We present how this knowledge transfer across domains enables a much faster and more accurate completion of host structures, compared to unconditioned diffusion models or previous approaches solely based on density-functional theory (DFT). Overall, when applied to a test dataset of hydrogen-containing materials from the MC3D database, our approach exceeds a success rate of 97% in terms of finding a structural match or predicting a more stable configuration (according to DFT) than the initial reference from the experimental source database (and with a success rate exceeding 99% when excluding structures flagged as theoretical in MC3D), both when starting from structures that were already relaxed with DFT, or when starting directly from the experimentally determined host structures.

en: Score-based diffusion models for accurate crystal-structure inpainting and reconstruction of hydrogen positions

aiida

display_name: aiida

dft

display_name: dft

generative-ai

display_name: generative-ai

machine-learning

display_name: machine-learning

mlip

display_name: mlip


en: Hydrogen carriers that enable efficient transport and on-demand release of molecular hydrogen (H2) are crucial for practical hydrogen-based energy systems. Hydrogen boride (HB) nanosheets, composed of boron and hydrogen in a 1:1 stoichiometric ratio, have promising potential as safe and lightweight hydrogen carriers owing to their high gravimetric hydrogen density (8.5 wt %). In particular, heating of HB nanosheets results in H2 release over a broad temperature range from 423 to 1473 K. However, the mechanism of the multimodal H₂ desorption remains unclear. In this work, we elucidate that the interlayer H···H distances (dH···H) determine the multimodal desorption of H2 especially in the lower-temperature range (< 623 K). HB nanosheets subjected to various temperatures under different H2 pressures were prepared to investigate the thermal stability of their bonding configurations. Infrared spectroscopy and temperature-programmed desorption measurements revealed the occurrence of hydrogen depletion while the bonding configuration remains unchanged. The first to third nearest dH···H, along with the numbers of the corresponding H···H pairs, were systematically calculated for four possible interlayer stacking types. The calculated H···H pairs distribution closely matched the experimental profile for the thermally induced H2 desorption, suggesting that the multimodal desorption of H2 in the lower-temperature range is governed by the distribution of hydrogen distances. This study elucidates the unique mechanisms of H2 formation in HB nanosheets and provides valuable insights into the design of two-dimensional hydrogen containing materials.

en: Interlayer hydrogen-hydrogen spacing regulates the formation of molecular hydrogen in hydrogen boride nanosheets

hydrogen-boride-nanosheet

display_name: hydrogen-boride-nanosheet

hydrogen-release

display_name: hydrogen-release

interlayer-space

display_name: interlayer-space

two-dimensional-materials

display_name: two-dimensional-materials


en: Van der Waals (vdW) interactions play a crucial role in the formation of various systems. Two-dimensional (2D) metals have attracted considerable attention due to their unique properties, particularly in applications where vdW interactions play a significant role.  In particular, a graphene template facilitates the self-assembly of 2D metal nanosheets. A study of vdW interactions between copperene and graphene has been carried out. The behavior of the binding energy of copperene/graphene is studied within the framework of DFT-D3.Collection of data, input and output files. Calculations were performed using Quantum ESPRESSO.

en: Long-range van der Waals forces between graphene and copperene: first principles calculations

input-files

display_name: input-files

output-files

display_name: output-files

quantum-espresso

display_name: quantum-espresso


en:
Accurately parameterizing the screened Coulomb interaction U is essential for predictive density-functional theory extensions, such as DFT+U and DFT plus dynamical mean-field theory (DFT+DMFT), which model strongly correlated electron systems. This dataset provides the comprehensive computational records for a systematic study mapping the physical equivalence between the two primary first-principles methods for determining this parameter: linear response theory (LRT) and the constrained random-phase approximation (cRPA). Using a unified framework of maximally localized Wannier functions applied to four prototypical transition-metal systems (CrO2, KCuF3, NiO, and Sr2FeO4), the work compares systematically the two methods for determining the U value.

To support the verification and extension of these physical insights, the repository contains the complete input and output files for the underlying quantum mechanical simulations. This includes cRPA calculations partitioned into distinct target orbital configurations, spanning d-only, d+p, and frontier Wannier subspaces, alongside LRT datasets computed both with and without exchange-correlation effects. The entire execution pipeline is preserved through shell scripts that document the automated workflows.

materialscloud

en:
Materials Cloud is a platform built to enable the seamless sharing and dissemination of resources in computational materials science, offering educational, research, and archiving tools; simulation software and services; and curated and raw data. These underpin published results and empower data-based discovery, compliant with data management plans and the FAIR principles.

In the Materials Cloud you can browse, explore, download, or deposit raw and curated data (in the Discover, Explore, and Archive sections); you can access cloud or redeployable simulation services (from AiiDAlab turnkey simulations to the Quantum Mobile virtual machine, the AiiDA registry of plugins and workflows, and the OSSCAR notebooks, in the Work section), and you can use all our educational material, tutorials and lectures (in the Learn section).

en: Materials Cloud

en: Bridging constrained random-phase approximation and linear response theory for computing Hubbard parameters

dftu

display_name: dftu

linear-response

display_name: linear-response

wannier-functions

display_name: wannier-functions


en: Spin Hall effect (SHE) in two-dimensional (2D) materials is promising to effectively manipulate spin angular momentum and identify topological properties. In this work, we implemented an automated Wannierization with spin-orbit coupling on 426 non-magnetic monolayers including 210 metal and 216 insulators. Intrinsic spin Hall conductivity (SHC) has been calculated to find candidates exhibiting novel properties. We discover that Y₂C₂I₂ has an unconventional SHE with canted spin due to low crystal symmetry, Ta₄Se₂ is a metallic monolayer with exceptionally high SHC, and the semi-metal Y₂Br₂ possesses efficient charge-to-spin conversion induced by anti-crossing in bands. Moreover, quantum spin Hall insulators are investigated for quantized SHC. The present work provides a high-quality Wannier Hamiltonian database of 2D materials, and paves the way for the integration of 2D materials into high-performance and low-power-consumption spintronic devices.

en: High-throughput calculations of spin Hall conductivity in non-magnetic 2D materials

envi

en: Environment

spin-hall-effect

display_name: spin-hall-effect


en: Predicting quasiparticle energies in materials requires expensive numerical evaluations of the electron self-energy. This limits calculations to ordered systems with small unit cells. Here, using symbolic regression, we show that the GW self-energy can be accurately approximated with compact analytical functions of physically motivated Kohn-Sham descriptors. These expressions can be learned from a single GW calculation in the ordered phase and remain accurate under symmetry breaking induced by quantum and thermal fluctuations, elastic deformations, and amorphous disorder. This development enables routine GW calculations of complex materials with thousands of atoms at a computational cost comparable to semi-local density functional theory. We demonstrate the accuracy of this approach for covalent semiconductors, ionic insulators, and two-dimensional materials. These results establish symbolic regression as a viable route to predictive, interpretable, and transferable many-body electronic structure models.

en: Electron correlation in semiconductors and insulators via symbolic regression

electronic-structure

display_name: electronic-structure

equation-discovery

display_name: equation-discovery

gw

display_name: gw

many-body-perturbation-theory

display_name: many-body-perturbation-theory

symbolic-regression

display_name: symbolic-regression


en: In the field of orthopedic biomechanics, synthetic bone surrogates are essential for evaluating surgical techniques, implant stability, and fracture risks due to their reproducible geometry and consistent mechanical behavior compared to human cadaveric tissue. Fourth-generation (4th Gen) Sawbones(R) composite models, which utilize a short fiber-filled epoxy (SFFE) cortical shell and a polyurethane foam (PUF) cancellous core, represent the industry standard. However, a significant gap remains in the literature regarding the full anisotropic characterization of these individual constituents, which is critical for high-fidelity numerical simulations. This study presents a comprehensive experimental dataset covering uniaxial tension (ASTM D638), compression (ASTM D695), and fracture toughness (ASTM E399) tests, alongside specialized shear characterization using a modified Single Cube Apparatus (SCA). The dataset includes 93 successful mechanical tests: 56 for the SFFE cortical surrogate and 37 for the PUF cancellous surrogate. The results validate the transverse isotropy of the SFFE and the isotropic behavior of the PUF. These findings provide the required mechanical properties for accurate finite element studies, facilitating the rigorous validation of synthetic bone surrogates as representations of biological human tissue.

en: Dataset for characterization of fracture and elastic properties of commercially available polyurethane foam and short fiber filled epoxy for bone models

anisotropy

display_name: anisotropy

bone-substitutes

display_name: bone-substitutes

characterization

display_name: characterization

experimental

display_name: experimental

fracture-toughness

display_name: fracture-toughness

sawbones

display_name: sawbones


en: IZ-DPscreen is a hybrid machine learning framework developed for the high-throughput screening of double perovskites. It employs a stacking regressor approach to accurately predict key material properties, including band gap, formation energy, and thermodynamic stability. By integrating multiple learning algorithms, the model enhances prediction reliability and robustness. The performance of IZ-DPscreen is validated through benchmarking against both theoretical (DFT) and available experimental data, demonstrating its capability for reliable materials screening. This approach enables the rapid identification of thermodynamically stable double perovskites with optimal band gaps, thereby accelerating the discovery of promising candidates for optoelectronic and energy applications.

en: A hybrid machine learning approach for high-throughput screening of thermodynamically stable double perovskites with optimal band gap

band-gap

display_name: band-gap

double-perovskite

display_name: double-perovskite

high-throughput-screening

display_name: high-throughput-screening

machine-learning

display_name: machine-learning

thermodynamic-stability

display_name: thermodynamic-stability


en: Rutile Sn1−x Gex O2 alloys are promising materials for high-power electronic applications due to their dopability and tunable ultra-wide band gaps. We use first-principles density functional theory and statistical mechanics to investigate the crystallographic, electronic, and thermodynamic properties of rutile Sn1−x Gex O2 alloys. We predict that the lattice parameters follow Vegard’s law, while band gaps calculated with the hybrid HSE06 functional exhibit strong bowing, consistent with experiment. We also predict that the disordered phase has a large positive mixing enthalpy and a slight tendency for Ge–Sn clustering, indicated by weakly negative short-range order parameters. This large positive mixing enthalpy produces a miscibility gap with a critical temperature above 2300 K, implying that the high Ge and Sn solubilities observed in thin-film synthesis cannot be explained by the incoherent phase diagram alone. We demonstrate that coherency strain substantially alters phase stability. Calculations of the coherent spinodal show significant suppression of the miscibility gap, reducing the critical temperature to ≈ 900 K. These coherent phase boundaries could account for the experimentally observed high solubilities at typical growth temperatures. Our results indicate that coherency strain stabilizes these metastable alloys and enables bandgap engineering in this ultrawide-bandgap material system.

en: Thermodynamic and electronic properties of rutile Sn1−x Gex O2 alloys from first principles

classical-statistical-mechanics

display_name: classical-statistical-mechanics

thermodynamics-of-mixing

display_name: thermodynamics-of-mixing


en: Nanoscale twin boundaries (TBs) effectively restrict the free motion of dislocations by intersecting with other TBs to realize high strength. However, the dislocations parallel to the TBs can glide along the TBs, resulting in detwinning for low strength. Herein, we present a triple-interlocked-nanotwinned (TIT) strategy for overcoming these inherent deficiencies. An Mg-9Li alloy was used as a proof-of-concept. The treated alloy had a large volume fraction of TIT interfaces (65.7%). It not only had a high yield strength of 508.6 MPa (approximately eleven times higher than that of the TIT-free sample) but also offered unprecedented ageing resistance, with a reduction in hardness of 6% after 730 days. The martensite-like phase transformation process concurrently triggers multiple-variant twins to form TIT structures. These TIT nets can effectively prohibit dislocation motion, reduce strengthening anisotropy, and disperse localized stress during the deformation process. This strategy of phase transformation twinning open a gate to fabricate other stronger metallic or ceramic nanotwinned bulk materials.

en: Triple-interlocked-nanotwinned bulk magnesium alloys with exceptional strength and ageing resistance

ageing-resistance

display_name: ageing-resistance

magnesium-alloys

display_name: magnesium-alloys

strength

display_name: strength

triple-interlocked-nanotwin

display_name: triple-interlocked-nanotwin


en: We introduce P3MaZe, a real-space particle–mesh electrostatic method that combines the standard short-range/long-range decomposition of Particle-Particle Particle-Mesh (P3M) electrostatics with the Mass-Zero constrained dynamics (MaZe) framework. In this formulation, the smooth long-range electrostatic potential is represented on a mesh as a zero-inertia auxiliary field, while the discretized Poisson equation is enforced as a holonomic constraint during molecular dynamics. By retaining the standard P3M decomposition, P3MaZe preserves the systematic accuracy controls associated with the real-space cutoff, the Ewald splitting, the mesh spacing, and the charge assignment procedure, while replacing the conventional multigrid Poisson solver by a constrained correction problem. The method is validated for molten NaCl and simple point-charge flexible water (SPC/Fw). Structural, translational, collective, and rotational dynamical observables are in quantitative agreement with those obtained with established electrostatic methods, including real-space P3M, and Ewald summation. The constrained formulation consistently requires fewer multigrid iterations than the corresponding real-space P3M solver while retaining the expected linear scaling with system size. These results establish P3MaZe as a promising new direction for scalable real-space electrostatics in large-scale molecular simulations.

en: P3MaZe: a Mass-Zero constrained-dynamics formulation of particle–mesh electrostatics

constrained-dynamics

display_name: constrained-dynamics

electrostatic-interactions

display_name: electrostatic-interactions

long-range-interactions

display_name: long-range-interactions

molecular-dynamics

display_name: molecular-dynamics


en: This dataset supports the theoretical investigation reported in the manuscript "Exceptionally high carrier mobility in hexagonal diamond". Based on first-principles analyses of the electronic structures, carrier mobilities, and electron-phonon coupling mechanisms in both cubic diamond and hexagonal diamond, this work demonstrates high carrier mobility in the heaxagonal phase and elucidates its physical origins. The dataset includes relevant data files for geometry optimisation, phonon dispersion, dynamical quadrupole tensors, G0W0 quasiparticle bands, and carrier mobility calculations.

materialscloud

en:
Materials Cloud is a platform built to enable the seamless sharing and dissemination of resources in computational materials science, offering educational, research, and archiving tools; simulation software and services; and curated and raw data. These underpin published results and empower data-based discovery, compliant with data management plans and the FAIR principles.

In the Materials Cloud you can browse, explore, download, or deposit raw and curated data (in the Discover, Explore, and Archive sections); you can access cloud or redeployable simulation services (from AiiDAlab turnkey simulations to the Quantum Mobile virtual machine, the AiiDA registry of plugins and workflows, and the OSSCAR notebooks, in the Work section), and you can use all our educational material, tutorials and lectures (in the Learn section).

en: Materials Cloud

carrier-mobility

display_name: carrier-mobility

electron-phonon-coupling

display_name: electron-phonon-coupling

hexagonal-diamond

display_name: hexagonal-diamond


en: We perform a first-principles high-throughput screening of the mechanical properties of phonon-mediated superconductors derived from the recent experimentally synthesized superconducting materials database PRX Energy \textbf{4}, 033012 (2025). We develop the aiida-mechanical workflow which combines first-principles calculations of elastic constants and generalized stacking fault energies, to assess the ductility of superconducting candidates. Starting from 250 materials identified with promising superconducting critical temperatures, we computed their elastic tensors to evaluate the bulk modulus, shear modulus, Pugh's ratio, and Pettifor's ratio. To further characterize their plastic deformation behavior, we calculated the stacking fault energy and surface energy for selected materials and slip directions, allowing the estimation of Rice's ratio and related ductility indicators. We find that several new materials simultaneously exhibit high Tc and ductility, including HfPd2Al, TiRuSb, and ZrNi2Ga. This dataset provides the complete computational provenance. Specifically, it contains the fully relaxed crystal structures, Quantum ESPRESSO calculations for all elastic tensor (finite-displacement and Born approximation methodologies) and stacking fault energy workflows, as well as k-point and supercell convergence tests. This work offers a quantitative mapping of mechanical performance across a wide range of superconductors and provides a valuable reference for finding new practical superconducting materials.

en: In search of novel ductile superconductors

ductility

display_name: ductility

elastic-tensor

display_name: elastic-tensor

generalized-stacking-fault-energy

display_name: generalized-stacking-fault-energy

pettifors-ratio

display_name: pettifors-ratio

pughs-ratio

display_name: pughs-ratio

rices-ratio

display_name: rices-ratio

superconductor

display_name: superconductor

surface-energy

display_name: surface-energy


en: The favourable thermodynamic properties of magnesium make it a promising negative electrode for rechargeable Mg-metal batteries. However, parasitic side reactions and uncontrolled deposition at the unstable electrode/electrolyte interface severely hinder reversible electrodeposition. Here we demonstrate that a high density of twin defects via cyclic-multidirectional deformation markedly increases the diffusion rate and simultaneously suppresses interfacial reactions. Comprehensive morphological characterisation combined with theoretical calculations reveals that the twinned-magnesium negative electrode exhibits significantly enhanced kinetics, leading to a reduced dimensionless electrochemical Damköhler number and indicating that magnesium deposition becomes less diffusion-limited.Furthermore, reorganisation energy analysis based on Marcus–Hush–Chidsey kinetics, in conjunction with the battery overpotential, indicates that the twin structure effectively mitigates parasitic reactions between the negative electrode and the electrolyte, thereby significantly reducing the passivation effect and enabling long-term reversible magnesium electrodeposition. Consequently, the designed twinned-magnesium electrodes in an asymmetric coin cell paradigm achieve a Coulombic efficiency of 99.53% over 2000 cycles at 30 mA cm-2 with a capacity of 2 mAh cm-2, competitive with reported magnesium metal negative electrodes. This simple strategy has been successfully extended to the zinc metal system as a proof of concept, demonstrating the universal potential of twin engineering for achieving reversible metal electrodeposition.

en: Twinned-magnesium metal negative electrodes enable reversible magnesium electrodeposition

envi

en: Environment

interface-passivation

display_name: interface-passivation

magnesium-electrodeposition

display_name: magnesium-electrodeposition

magnesium-metal-negative-electrodes

display_name: magnesium-metal-negative-electrodes

twinning

display_name: twinning


en: The quality, consistency, and information content of training data is often what determines the practical value of machine-learning models for atomistic simulations. Yet, many widely used electronic-structure databases are assembled having materials screening as primary goal rather than robust force-field learning, are limited in their scope to a specific class of chemical compounds, and/or employ inconsistent DFT functionals and settings. Here we introduce MAD-1.5, a highly curated dataset designed explicitly for training broadly applicable atomistic models across the periodic table at high levels of theory. MAD-1.5 extends the MAD dataset with targeted enrichment strategies that improve the coverage of chemical space to 102 elements while keeping the total number of configurations compact. All structures are computed with a single, standardized all-electron DFT workflow using the r2SCAN meta-GGA functional and consistent convergence settings, ensuring uniformity across chemically heterogeneous systems. The dataset encompasses molecules, clusters, bulk crystals, surfaces, and low-dimensional structures, and its quality and consistency are further enhanced by outlier removal using uncertainty quantification. We demonstrate the high accuracy that can be achieved with the proposed dataset by training PET-MAD-1.5, a generally applicable r2SCAN interatomic potential that covers 102 elements in the periodic table and achieves exceptional levels of benchmark accuracy and stability in challenging simulation protocols.

en: High-quality, high-information datasets for universal atomistic machine learning

atomistic-simulations

display_name: atomistic-simulations

dataset

display_name: dataset

density-functional-theory

display_name: density-functional-theory

interatomic-potentials

display_name: interatomic-potentials

machine-learning

display_name: machine-learning

universal-models

display_name: universal-models


en: Dynamical control of the optical nonlinear properties in solids – with light itself – will be essential for the development of ultrafast photonic technologies, including high-speed terahertz-rate data communication and advanced signal processing. Previously, methods for optically modulating nonlinear optical processes, such as second harmonic generation (SHG), have relied predominantly on non-resonant light-matter interaction or photo-generation of hot electrons in nanoscale materials. However, these approaches are typically constrained by limited interaction lengths and the initial frequency conversion is relatively weak under equilibrium conditions, making them impractical for devices that require high-contrast switching of strong signals. Here, modulation of a strong SHG signal in a bulk β-BaB2O4 (BBO) nonlinear optical crystal is achieved through resonant transient lattice deformation induced by intense terahertz (THz) pulses tuned to a specific infrared-active phonon mode. Selective lattice excitation results in an unprecedented ~30% modulation of the SHG in BBO. In contrast to past efforts employing non-resonant THz interaction, this effect cannot be explained by modulation of the nonlinear susceptibility – a 𝜒(3)-effect. But rather – through polarization-resolved measurements, ab initio calculations, and analytical modelling –the SHG modulation is found to be driven by THz-induced phonon dynamics that affect the nonlinear optical phase-matching conditions through a 𝜒(2) process. This resonant all-optical control mechanism points toward new optical control schemes, based on selected lattice degrees of freedom, to dynamically tune the overall nonlinear optical response in bulk materials. Such schemes may find practical applications in ultrafast optoelectronics and integrated photonics.

en: All-optical control of second-harmonic generation in β-BaB2O4 via coherent, terahertz-driven acentric lattice displacement

all-optical-control-in-bulk-crystals

display_name: all-optical-control-in-bulk-crystals

nonlinear-optical-phase-matching

display_name: nonlinear-optical-phase-matching

nonlinear-susceptibility

display_name: nonlinear-susceptibility

resonant-lattice-dynamics

display_name: resonant-lattice-dynamics

second-harmonic-generation

display_name: second-harmonic-generation

terahertz-phonon-excitation

display_name: terahertz-phonon-excitation


en: The Shastry-Sutherland compound SrCu2(BO3)2 (SCBO) is a paradigmatic low-dimensional quantum spin system, featuring geometrically frustrated interacting spin dimers and a rich landscape of emergent quantum phenomena. While its magnetic properties have been extensively explored, the nature of its electronic excitations - particularly the Cu2+ d–d transitions - remains poorly understood. A detailed characterization of these excitations is essential to determine the crystal field splitting and the degree of Cu 3d–O 2p hybridization, both of which underpin superexchange interactions and magnetic behavior in SCBO. Here, the electronic properties of SCBO are investigated by combining spectroscopic techniques with theoretical approaches for first-principles band structure calculations.Experimentally, we employ L3-edge resonant inelastic x‑ray scattering (RIXS) to directly probe intra-d excitations, supplemented by broadband infrared reflectivity and ellipsometry measurements to resolve charge-transfer (CT) features. Theoretically, multireference quantum chemistry calculations accurately reproduce the energies (1.8–2.4 eV) and symmetries of the observed d–d excitations, while band-structure calculations based on density functional theory elucidate the CT excitation spectrum. These combined approaches define the energy scales for both d–d and CT transitions, validate the computational framework, and provide quantitative microscopic parameters essential for refining superexchange-based magnetic models in this prototypical frustrated quantum antiferromagnet.

en: Probing high-energy electronic excitations in the Shastry-Sutherland compound SrCu2(BO3)2 with resonant inelastic x-ray scattering and optical spectroscopy

d-d-excitations

display_name: d-d-excitations

dftu

display_name: dftu

resonant-inelastic-x-ray-scattering

display_name: resonant-inelastic-x-ray-scattering

shastry-sutherland-model

display_name: shastry-sutherland-model


en: We developed a machine learning interatomic potential (MLIP) for Ge-rich GeSbTe alloys of interest for applications in phase change memories embedded in microcontrollers. The MLIP was generated by fitting with a neural network method a large database of energies and forces computed within density functional theory of elemental, binary, stoichiometric and non-stoichiometric ternary alloys in the Ge-Sb-Te phase diagram. The MLIP is demonstrated to be highly transferable to large regions of the phase diagram around the compositions included in the dataset. The MLIP is then exploited to simulate the crystallization with phase separation of three Ge-rich alloys on the Ge-SbTe and Ge- GeSbTe tie-lines that correspond to the set process of the memory cell. The transformation on the ns time scale and at 600 K, comparable to the operation conditions of the memory, yields crystalline cubic GeTe slightly Sb-doped and amorphous GeSb and Ge. These metastable phases differ from the thermodynamically stable products and form due to kinetics effects on the short time span of the set operation in phase change memories.

en: On phase separation and crystallization of Ge-rich GeSbTe alloys from atomistic simulations with a machine learning interatomic potential

database

display_name: database

interatomic-potential

display_name: interatomic-potential


en: Contact variability remains a major obstacle for scaled two-dimensional transistors, but the extent to which contact geometry can control defect sensitivity remains unclear. This dataset supports a first-principles comparison of top and recessed Ti-MoS2 contacts under a common ordered sulfur-vacancy sequence. The deposited data include VASP POSCAR-format atomic structures generated from NanoDCAL device geometries, the corresponding NanoDCAL SCF input files used as structure sources, and processed metadata tables documenting vacancy coordinates, contact geometries, convergence status and Schottky-barrier-height extraction. These data support the manuscript conclusion that recessed Ti contacts strongly reduce vacancy-position-dependent carrier-injection-barrier variation in MoS2 relative to conventional top contacts.

en: Defect-tolerant carrier injection in MoS2 enabled by recessed Ti contacts

recessed-contact

display_name: recessed-contact

schottky-barrier

display_name: schottky-barrier


en: We present an efficient first-principles approach for simulating the nonequilibrium electron dynamic in extended systems beyond the linear regime. The method combines Koopmans-compliant functionals, which provide an accurate description of quasiparticle band structures, with the real-time evolution of the electronic density matrix in a Wannier basis within the Hartree plus screened exchange (HSEX) approximation. The locality of the orbital basis enables physically justified approximations that significantly reduce the computational and memory scaling of the method while preserving accuracy. We benchmark the approach in the linear regime against experimental spectra and reference GW-BSE calculations for systems featuring both weakly and strongly bound excitons. Moving to the nonlinear regime, we investigate high-harmonic generation (HHG) in silicon and lithium fluoride. While in silicon the HHG spectrum is largely governed by the quasi-particle band structure, we find that in materials featuring strong excitonic effect such as LiF the harmonic emission is selectively enhanced at excitonic resonances, suggesting that HHG probes correlated electron-hole excitations rather than solely the quasiparticle band structure. The present framework enables fully ab initio simulations of excitonic effects in nonlinear optical spectra at a significantly reduced computational cost compared to real-time many-body approaches, providing an efficient route to the study of ultrafast and strong-field phenomena in solids.

materialscloud

en:
Materials Cloud is a platform built to enable the seamless sharing and dissemination of resources in computational materials science, offering educational, research, and archiving tools; simulation software and services; and curated and raw data. These underpin published results and empower data-based discovery, compliant with data management plans and the FAIR principles.

In the Materials Cloud you can browse, explore, download, or deposit raw and curated data (in the Discover, Explore, and Archive sections); you can access cloud or redeployable simulation services (from AiiDAlab turnkey simulations to the Quantum Mobile virtual machine, the AiiDA registry of plugins and workflows, and the OSSCAR notebooks, in the Work section), and you can use all our educational material, tutorials and lectures (in the Learn section).

en: Efficient nonequilibrium electron dynamics from first-principles: leveraging Koopmans spectral functionals and Wannier localization

ab-initio

display_name: ab-initio

electron-dynamics

display_name: electron-dynamics

high-harmonic-generation

display_name: high-harmonic-generation

koopmans-functionals

display_name: koopmans-functionals

nonequilibirum

display_name: nonequilibirum

optical-absorption

display_name: optical-absorption

real-time-dynamics

display_name: real-time-dynamics


en: Nonbenzenoid carbocyclic rings are postulated to serve as important structural elements toward tuning the chemical and electronic properties of extended polycyclic aromatic hydrocarbons (PAHs, or namely nanographenes), necessitating a rational and atomically precise synthetic approach toward their fabrication. This record contains data supporting a recent work where, using a combined bottom-up in-solution and on-surface synthetic approach, we report the synthesis of nonbenzenoid open-shell nanographenes containing two pairs of embedded pentagonal and heptagonal rings.

materialscloud

en: Materials Cloud

en: Open-shell Non-benzenoid Nanographenes Containing Two Pairs of Pentagonal and Heptagonal Rings

nanographene

display_name: nanographene

on-surface-synthesis

display_name: on-surface-synthesis

polycyclic-aromatic-hydrocarbons

display_name: polycyclic-aromatic-hydrocarbons

scanning-tunneling-microscopy

display_name: scanning-tunneling-microscopy


en: The upgrade of the 3rd generation synchrotrons to diffraction-limited storage rings will enable a gain of up to two orders of magnitude in brilliance and further enable the creation of multiple macromolecular crystallography (MX) beamlines capable of delivering fluxes in excess of 1x10^15 photons·s−1; here called extremely high flux (EHF) MX beamlines. These beamlines, such as ID29, ESRF-EBS, BioCARS, APS-U, and MicroMAX, MAX IV, have all either been partly or solely geared toward delivering time-resolved MX experiments at room temperature and realising microsecond time resolutions. Given the uncharted territory of using dose rates in excess of 50 GGy·s−1 at many facilities, this article has examined some of the expected consequences suggesting that considerable attention should be paid to beam heating effects for < 20 μm crystals exposed to 1x10^15 photons·s−1. Several strategies have been proposed to mitigate heating effects when high dose rates are required for a time-resolved experiment, including reducing the absorbed dose by increasing the size of the crystal and the beam profile and explicitly exploiting the motion of the crystal in serial crystallography delivery systems. The model presented here is intended to serve as a useful tool to inform experimental design and support users’ decision-making in such cases.

en: The PSI Data Catalog is the central repository directory for scientific metadata generated at the Paul Scherrer Institut (PSI). Powered by SciCat—a community-driven, open-source metadata management framework co-developed by PSI—the catalog provides discoverability and standardized access pathways to petabyte-scale datasets produced across PSI’s large-scale research facilities, including the Swiss Light Source (SLS), the Swiss Spallation Neutron Source (SINQ), and the SwissFEL X-ray free-electron laser.

en: PSI Data Catalog

de: PSI Data Catalog

fr: PSI Data Catalog

it: PSI Data Catalog

de: PSI Open Data Provider

en: Modelling of radiation damage and beam induced crystal heating of room-temperature samples at extremely high flux MX beamlines for time-resolved crystallography applications

value: DCAT Harvester SciCat

envi

en: Environment


en:
CryoEM dataset of Apoferritin collected on a FEI Titan Krios G4 microscope equipped with a Falcon 4i detector.
First public dataset of the OpenEM project. For more information on the project: https://swissopenem.github.io

en: Apoferritin


en: Energy flows among coupled subsystems are essential for ultrafast dynamics and high-speed technologies. In magnetic materials, spin fluctuations -magnons- mediate these flows in ultrafast magnetism. Yet momentum-resolved access to low-energy magnons governing the microscopic dynamics has been lacking. Using time-resolved resonant diffuse scattering alongside complementary time-resolved X-ray techniques and quantum-kinetic simulations, we unveil the hierarchical energy pathways among correlated systems in the photoexcited antiferromagnet CuO. Above-bandgap excitation triggers near-instantaneous spin disorder, generating non-thermal magnons throughout reciprocal space within femtoseconds. Real-time momentum-resolved tracking reveals picosecond magnon quasi-thermalization, followed by nanosecond recovery via momentum-selective magnon-phonon scattering. The quasiparticle dispersion mismatch creates recovery bottlenecks that control non-equilibrium lifetimes. This microscopic framework transcends phenomenological models and generalizes across materials, establishing design principles for ultrafast control of material properties.

en: Hierarchical quasiparticle dynamics in antiferromagnets revealed by time- and momentum-resolved X-ray scattering


en: The goal of this proposal is to explore the competition between electron and energy transfer from photoexcited tryptophan to the heme group in ferrous and ferric Cytochrome c in physiological media. Cyt c contains only one tryptophan amino-acid residue, whose decay is still debated. While previous works alluded to an energy transfer, our recent experimental and theoretical studies raise the question of a competing electron transfer process, possibly simultaneous to a back-electron transfer in a Dexter process. This question can be resolved by monitoring the response of the central iron atom via femtosecond X-ray emission and X-ray absorptions, only possible due to the high peak brightness and short pulse duration of x-ray FELs.

en: Energy vs Electron Transfer Tryptophan-to-Heme in Cytochrome C


en:
Supporting data for Ferajoui et.al. A 1 Megapixel charge integrating hybrid pixel detector for electron diffraction JINST 20 202510.1088/1748-0221/20/12/C12007

The research leading to these results has received funding from the Swiss National Science Foundation
(Grant n◦ 215650) and the Austrian Science Fund (Grant n◦
I 6546-N).

en: Sparse electron data recorded with Jungfrau


en: This repository contain the experimental data for  the magnetic orders and excitations of the distorted kagome intermetallic magnet TmAgGe published in Phys. Rev. B 107, 224419 (2023). Single crystal diffraction and inelastic neutron diffraction was carried out on the Zebra and CAMEA beamlines at the Paul Scherrer Institut.

en: camea zebra sinq magnetic-excitations magnetic-structure tmagge

en: Magnetic ground state and perturbations of the distorted kagome Ising metal TmAgGe

camea

display_name: camea

magnetic-excitations

display_name: magnetic-excitations

magnetic-structure

display_name: magnetic-structure

sinq

display_name: sinq

tmagge

display_name: tmagge

zebra

display_name: zebra


en:
This dataset contains radially integrated scattering data from narwhal tusk slices measured to investigate the tusk’s unique spiral structure with highly anisotropic mechanical properties. The full dataset comprises approximately 4400 scan folders, each corresponding to an line of a 2D grid scan. The subset associated with the publication by A. Rodriguez-Palomo, M. Liebi, H. Birkedal et al., “The narwhal tusk assembles its macroscopic helix from building blocks with opposing twists”, Nature Communications (2026), includes thin slices from two male narwhal tusks measured in transversal and longitudinal orientations.

The publication-relevant samples are: tusk 1, ID001 (transversal cut, scans 03115-03465), ID002 (transversal cut, scans 02714-03114), ID009 (longitudinal cut, scans 01767-02067), and ID010 (longitudinal cut,  scans 00702-01077); tusk 2, ID022 (transversal cut, scans 02068-02412), ID027 (transversal cut, scans 01078-01465), ID028 (longitudinal cut, scans 02413-02713), and ID029 (longitudinal cut, scans 01466-01766). These scan ranges identify the data used in the associated article within the larger dataset.


en:
The extinct plant group Bennettitales (Cycadeoidales) was a prominent part of Mesozoic vegetation. The group has been studied extensively and for more than 100 years it has been central in discussions of the relationships among the major groups of seed plants in which extinct plants were also considered. Despite much effort the phylogenetic position of the Bennettitales is still unresolved with a major obstacle being uncertainty about how to interpret the organisation and structure of the seed. The most widely accepted interpretation has been that the seed, like the seeds of most conifers, has a single integument around the nucellus and lacks any additional coverings. An alternative interpretation is that the seed integument is surrounded by an envelope comparable to the situation in extant Gnetales and extinct Erdtmanithecales. The petrified seed cone of Cycadeoidea (Bennettites) morierei described in the late nineteenth century from the Early Cretaceous of Normandy is one of the most informative bennettitalean reproductive structures with its superb preservation offering great potential for resolving the unsettled discussion regarding seed structure in Bennettitales.
	C. morierei was carefully documented by Octave Lignier in his monumental study “Végétaux fossiles de Normandie. Structure et affinités du Bennettites morierei Sap. & Mar. (sp.)” from 1894, but despite his meticulous analysis of the fossil, Lignier left certain questions open in his interpretation and in his widely cited reconstruction of the structure of the seed. In the paper associated with the datasets provided here we have re-examined fragments of Cycadeoidea morierei using synchrotron X-ray tomographic microscopy (SRXTM) to attempt to answer some of these open questions.
	Cycadeoidea morierei is based on a single petrified seed cone. The specimen was fractured by Lignier, who prepared several thin sections, in longitudinal as well as transverse directions in preparing his account. The original material was stored at the University of Caen, France, but most was lost during the second World War. However, several larger and smaller fragments of the seed cone were later recovered at the university and made available for the present study. Among the fragments studied using SRXTM were small isolated, abraded seeds and interseminal scales (e.g., fragments 6 and 8) and a few small groups of fractured seeds and interseminal scales still tightly packed together (e.g., fragment 17). Typically, these small fragments are broken at the base and only rarely are remains of the seed stalk preserved. One larger fragment (fragment 24) consists of several seeds with seed stalks intact. For comparison with Cycadeoidea morierei we also examined a fragment of another classic petrified seed cone, Cycadeoidea gibsoniana from the Early Cretaceous of isle of Wight, Southern England, using SRXTM. The results, combined with a comparative survey of other fossil material, indicate that the seeds of Bennettitales had at least one, perhaps two, envelopes covering the integument, comparable to what is seen among extant Gnetales, extinct Erdtmanithecales, and diverse fossil seeds recovered from Early Cretaceous mesofossil assemblages. Most of the SRXTM analyses of the Cycadeoidea material were carried during 2009-2023 on the TOMCAT beamline, SLS, Paul Scherrer Institute, Villigen, Switzerland. Fragment 24 was analysed at the new I-TOMCAT beamline at SLS in November 2025.

en: Synchrotron radiation X-ray tomographic microscopy datasets for seed structure in Cycadeoidea morierei


en: Aligned complex-valued projections and tomographic datasets from 3 PXCT acquisitions on the same catalyst specimen primarily composed of zeolite, alumina, and nickel, acquired at 3 different photon energies close to the nickel absorption edge. The file information.txt contains a description of the data. We also include the software scripts used to process the data.

en: The PSI Data Catalog is the central repository directory for scientific metadata generated at the Paul Scherrer Institut (PSI). Powered by SciCat—a community-driven, open-source metadata management framework co-developed by PSI—the catalog provides discoverability and standardized access pathways to petabyte-scale datasets produced across PSI’s large-scale research facilities, including the Swiss Light Source (SLS), the Swiss Spallation Neutron Source (SINQ), and the SwissFEL X-ray free-electron laser.

en: PSI Data Catalog

en: Aligned complex-valued projections and 3D tomographic datasets from a catalyst specimen


en:
This repository contains the complete dataset and associated software supporting the publication:
“In-Situ Ptychographic Nanotomography Captures Activation, Mobility, and Deactivation of Supported Catalysts”

The data were acquired using in-situ ptychographic X-ray computed nanotomography (PXCT) and used to investigate structural evolution of Pd-on-silica catalysts under methane oxidation conditions.
Experiments were performed at the cSAXS beamline of the SLS.

The dataset includes raw diffraction data, reconstructed projections, 3D electron density tomograms, and analysis/reconstruction codes.

Codes:
cxs_software_ptychography/  Contains ptychographic reconstruction routines (phase retrieval, scan handling, preprocessing).
cxs_software_tomography/    Contains tomographic reconstruction and 3D volume processing tools.

Raw Data
S03000-03999_ID ...     Raw diffraction datasets acquired during in-situ scanning nanotomography experiments

Reconstructed Data
analysis_S03000-03999 ...    Includes phase and/or amplitude porjection reconstructions
reconstructed_tomograms    Volumetric datasets derived from ptychographic projections used for analysis

en: Data and Software Supporting: In-Situ Ptychographic Nanotomography Captures Activation, Mobility, and Deactivation of Supported Catalysts

envi

en: Environment

heterogeneous-catalysis

display_name: heterogeneous-catalysis

x-ray-ptychography

display_name: x-ray-ptychography

x-ray-tomography

display_name: x-ray-tomography


en: We investigated field electron emission from graphene on SiO₂/Si substrate. Graphene layer was structured into wire-shaped patterns with widths down to five microns using photolithography and etching. Field emission characteristics were measured using a scanning anode setup, wherein a sharp metal needle was positioned approximately 10 microns above the substrate and scanned across the graphene wires. Emission from the cleaved edges of the graphene wires was also examined. We observed electron emission primarily near the graphene edges, suggesting that the atomically thin structure and edge geometry of suspended graphene make it a promising candidate for high-brightness electron sources.

en: Field Emission From Edges of Lithographically Patterned Graphene Wires


en: Varying the chemical consistency of acoustically levitated droplets opens up an in situ study of chemical and biochemical reactions in small volumes. However, the optimization of the mixing time and the minimization of the positional instability induced by solution dispensing are necessary for practical applications such as the study of the transient state of macromolecules crystallography during the ligand binding processes. For this purpose, we study the inertial mixing in a configuration compatible with the room-temperature crystallography using the acoustic levitation diffractometer, therein solution drops ejected at high velocity collide and coalesce with droplets dispensed on acoustically levitated and rotating polymer thin-film sample holders. With the proposed method, we are able to achieve the mixing time of ∼0.1 s for sub-micro and a few microliter droplets. The observed short mixing time is ascribed to the rapid penetration of the solution into the droplets and confirmed by a computational fluid dynamic simulation. The demonstrated accelerated solution mixing is tested in a pilot time-lapse protein crystallography experiment using the acoustic levitation diffractometer. The results indicate the detection of transient ligand binding state within 2 s after the solution dispensing, suggesting the feasibility of the proposed method for studying slow biochemical processes.

en: Inertial mixing of acoustically levitated droplets for time-lapse protein crystallography


en: The controlled rotation of acoustically levitated samples is beneficial for analyzing sample properties, e.g., in a recently reported room temperature x-ray diffraction experiment, wherein thin film sample holders comprising thin film disks with short blades attached around their circumference were utilized. However, the mechanism of producing the torque and the determinant factor of the rotation direction for these planar ultrasonic rotors have been elusive. We, therefore, study the impact of the size and shape on the rotation characteristics of these ultrasonic rotors in air and further study the influence of the viscosity of fluid. Theory and experiment demonstrate the essential role of the short blades in producing the acoustic torque both in air and water. In the airborne case, the shape and arrangement of the blades are found to determine the rotation direction. In water, with a dynamic viscosity 55 times higher than that of air, we demonstrate that ultrasonic rotors down to 25-um-disk-diameter function in an optimized experimental geometry with approximately the same actuation efficiency as in air. Our results will be beneficial to further improve the applicability of the ultrasonic rotors as sample holders for airborne experiments and to explore the micrometer-scale ultrasonic rotors in liquid.

en: Size and shape dependent rotation characteristics of thin film ultrasonic rotors


en: The transverse structure of field-emission electron wave packets is governed by cathode material and geometry through the near-apex electrostatic potential, which induces electrostatic defocusing and spatial transmission filtering. To study these effects, we develop a framework for field-emission wave-packet propagation that combines finite-element electrostatic potentials with paraxial Schroedinger propagation under an effective parabolic transverse-potential approximation, together with barrier-side spatial filtering. Applied to nanometer-scale prolate hemispheroidal emitters, the method enables efficient wave-packet calculations that reproduce the expected electron-optical defocusing and show how tunneling-induced narrowing can amplify subsequent transverse expansion. We further apply the framework to a two-dimensional film-edge model of a graphene edge emitter, where the Angstrom-scale initial width leads to stronger transverse expansion. The resulting wave packets are then used to study coherent multi-site superposition, predicting either overall beam narrowing or fragmentation into multiple beamlets, which may contribute to the striated field-emission-microscopy patterns reported for graphene edges.

en: Transverse structure of field-emission electron wave packets from nanometer-scale hemispheroidal cathodes and two-dimensional film edge emitters


supersampled-microscopy-dataset

en: Supersampled microscopy dataset

title_for_slug: supersampled-microscopy-dataset


en: Historical motion-picture films can become brittle, warped, shrunken, or fused, rendering them unreadable by conventional scanners because they can no longer be safely unrolled or transported under tension. X-ray tomography has already transformed the study of fragile cultural artifacts, including rolled medieval scrolls and the Herculaneum papyri. Similarly, we intend to measure rolled black and white motion-picture film by exploiting the strong X-ray absorption of the silver image layer at the TOMCAT beamline to investigate feasibility. Synchrotron hard X-ray tomography is attractive because it combines high flux, a parallel beam, and phase sensitivity. This enables fast scans with high signal-to-noise ratio, while phase contrast can enhance film boundaries and residual emulsion structures.

en: Back to light: Resurrecting lost film rolls using X-ray tomography


en: Demonstration dataset collected with JUNGFRAU 4M at X06SA beamline

en: The PSI Data Catalog is the central repository directory for scientific metadata generated at the Paul Scherrer Institut (PSI). Powered by SciCat—a community-driven, open-source metadata management framework co-developed by PSI—the catalog provides discoverability and standardized access pathways to petabyte-scale datasets produced across PSI’s large-scale research facilities, including the Swiss Light Source (SLS), the Swiss Spallation Neutron Source (SINQ), and the SwissFEL X-ray free-electron laser.

en: JUNGFRAU detector for brighter X-ray sources - solutions for IT and data science challenges in macromolecular crystallography


en: In the associate article to these data sets, we present an X-ray tomographic imaging method that is well suited for pulmonary disease studies in animal models, to resolve the full pathway from gas intake to gas exchange. Current state-of-the-art synchrotron-based tomographic phase-contrast imaging methods allow for three-dimensional microscopic imaging data to be acquired non-destructively in scan times of the order of seconds with good soft tissue contrast. However, when studying multi-scale hierarchically structured objects, such as the mammalian lung, the overall sample size typically exceeds the field of view illuminated by the X-rays in a single scan, and the necessity for achieving a high spatial resolution conflicts with the need to image the whole sample. Several image-stitching and calibration techniques to achieve extended high-resolution fields of view have been reported, but those approaches tend to fail when imaging non-stable samples, thus precluding tomographic measurements of large biological samples, which are prone to degradation and motion during extended scan times. In this work, we demonstrate a full-volume three-dimensional reconstruction of an intact rat lung under immediate post mortem conditions and at an isotropic voxel size of (2.75 µm)^3. We present the methodology for collecting multiple local tomographies with 360 degree extended field of view scans followed by locally non-rigid volumetric stitching. Applied to the lung, it allows to resolve the entire pulmonary structure from the trachea down to the parenchyma in a single dataset.

en: PSI Data Catalog

en: Micrometer-resolution X-ray tomographic imaging of a complete intact post mortem juvenile rat lung


en: The experiment aims at visualizing with high resolution stacking faults in InSb micropillars that were deformed in a microcompression experiment. The chosen method is ptychographic topography, a new method recently developed at the cSAXS beam line.

en: Visualization of stacking faults in InSb micropillars by ptychographic topography

envi

en: Environment


amr-solver-data

en:
Data of the paper "On architecture and performance of adaptive mesh refinement in an electrostatics Particle-In-Cell code" published in Computer Physics Communications.
The data is generated as part of the PhD thesis funded by the Swiss National Science Foundation (SNSF) under contract number 200021_159936.

en: AMR solver data

title_for_slug: amr-solver-data


en: Data of the paper "Matching of turn pattern measurements for cyclotrons using multiobjective optimization" published in Physical Review Accelerators and Beams. The data is generated as part of the PhD thesis funded by the Swiss National Science Foundation (SNSF) under contract number 200021_159936.

en: Data of turn pattern matching between measurement and simulation of the PSI Ring Cyclotron


en: Data of the paper "Global sensitivity analysis on numerical solver parameters of Particle-In-Cell models in particle accelerator systems" published in Computer Physics Communications. The data is generated as part of the PhD thesis funded by the Swiss National Science Foundation (SNSF) under contract number 200021_159936.

en: Data of of a global sensitivity study of the PSI Injector 2, PSI Ring Cyclotron, IsoDAR and AWA RF gun


en: Long-wavelength pulses from the Swiss X-ray free-electron laser (XFEL) have been used for de novo protein structure determination by native single-wavelength anomalous diffraction (native-SAD) phasing of serial femtosecond crystallography (SFX) data. In this work, sensitive anomalous data-quality indicators and model proteins were used to quantify improvements in native-SAD at XFELs such as utilization of longer wavelengths, careful experimental geometry optimization, and better post-refinement and partiality correction. Compared with studies using shorter wavelengths at other XFELs and older software versions, up to one order of magnitude reduction in the required number of indexed images for native-SAD was achieved, hence lowering sample consumption and beam-time requirements significantly. Improved data quality and higher anomalous signal facilitate so-far underutilized de novo structure determination of challenging proteins at XFELs. Improvements presented in this work can be used in other types of SFX experiments that require accurate measurements of weak signals, for example time-resolved studies.

en: Advances in long-wavelength native phasing at X-ray free-electron lasers


en: In the associated article to these datasets, we describe a new genus and species of an extinct magnoliid flower based on coalified fossils extracted from the Early Cretaceous Catefica mesofossil flora of Portugal. Internal structures of the fossils were investigated using synchrotron radiation X-ray tomographic microscopy at the TOMCAT Beamline, Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland. Phylogenetic analyses using external and internal features indicate relationship to Canellales and Magnoliales.

en: Synchrotron radiation X-ray tomographic microscopy datasets for the Early Cretaceous flower Catanthus dolichostemon E.M.Friis, P.R.Crane & K.R.Pedersen from Portugal


en: In the associated article to these datasets, we describe three new genera, Atlantocarpus E.M.Friis, K.R.Pedersen & P.R.Crane, Lambertiflora E.M.Friis, K.R.Pedersen & P.R.Crane and Mugideiriflora E.M.Friis, K.R.Pedersen & P.R.Crane from the Early Cretaceous of eastern North America and Portugal. Internal structures of the fossils were investigated using synchrotron radiation X-ray tomographic microscopy at the TOMCAT Beamline, Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland. All three genera are characterized by their multiparted and apocarpous gynoecium. Phylogenetic analyses using external and internal features indicate relationship to early diverging angiosperms and the fossils add to the growing evidence of extensive extinctions early in the history of angiosperms.

en: The PSI Data Catalog is the central repository directory for scientific metadata generated at the Paul Scherrer Institut (PSI). Powered by SciCat—a community-driven, open-source metadata management framework co-developed by PSI—the catalog provides discoverability and standardized access pathways to petabyte-scale datasets produced across PSI’s large-scale research facilities, including the Swiss Light Source (SLS), the Swiss Spallation Neutron Source (SINQ), and the SwissFEL X-ray free-electron laser.

en: Synchrotron radiation X-ray tomographic microscopy datasets for Atlantocarpus, Lambertiflora and Mugideiriflora from the Early Cretaceous of eastern North America and Portugal


en: In the related publication, we introduce a new application of time-resolved X-ray tomography (XRT) to imaging of the washcoating process in catalytic monolith filters with a honeycomb structure (DPF, GPF). The method is applied to several alumina washcoats with different particle size distributions deposited on a cordierite substrate. The results bring new insights into the drying dynamics of the porous filter wall as well as the on-wall catalyst layer, including the process of layer shrinking and cracking. The XRT results are supplemented by cross-section scanning electron microscopy images and mercury intrusion porosimetry of the final structures. In addition to the statistical analysis of the washcoat distribution, the impact of the washcoat structure on filter pressure loss is determined by  experiments.

en: PSI Data Catalog

en: Washcoating of catalytic particulate filters studied by time-resolved X ray tomography


en: In the related publication to these data sets, we explore the flow dynamics for two-phase flow in a porous medium (a bioclastic carbonate rock). We use state-of-the-art synchrotron X-ray tomography to capture the fluid dynamics within the pore space, with a scan time of 1 second and a temporal resolution (scan repetition rate) of 2 s. The rock sample was initially saturated with brine (DI water doped with 15%wt. KI) before brine and nitrogen gas were injected simultaneously. As the gas establishes a path through the pore space, the flow dynamics are transient. Eventually, an equilibrium is established, where the gas saturation oscillates about a constant mean value; this is referred to as steady state. There are 5 data sets, 3 of which capture the unsteady state dynamics, and 2 of which capture the steady state dynamics. The images were captured with a voxel size of 2.75 µm3. In these data sets we observe that the pore scale dynamics evolve as the macroscopic flow transitions from unsteady state to steady state. We observe that the saturation of the gas plateaus out before the differential pressure across the core. This suggests that gas phase is more mobile during unsteady state.

en: Real-Time Imaging Reveals Distinct Pore-Scale Dynamics During Transient and Equilibrium Subsurface Multiphase Flow

envi

en: Environment


en: In the publication associated with this data collection, we present a methodological framework suitable for reconstruction of the whole mouse brain cerebral microvasculature by synchrotron radiation X-ray tomographic phase-contrast microscopy with isotropic pixel size of 0.65 μm. The technique allows morphological measurements of even the smallest capillary vessel branches over the entire brain. In this data collection we provide some original tomographic images produced by the method, and an analysis code that can make a segmentation of the vessels and extract the vessel graph from the images.

en: Micrometer-resolution tomographic reconstructions of whole mouse brain microvasculature and an analysis program


en: In the corresponding article to these data sets, we explore the flow dynamics for two-phase flow in a porous medium (a bioclastic carbonate rock). We use state-of-the-art synchrotron X-ray tomography to capture the fluid dynamics within the pore space, with a temporal resolution of 1 s. The rock sample was initially saturated with brine (DI water doped with 15%wt. KI) before brine and nitrogen gas were injected simultaneously. As the gas establishes a path through the pore space, the flow dynamics are transient. Eventually, an equilibrium is established, where the gas saturation oscillates about a constant mean value; this is referred to as steady state. There are 9 data sets, with all the dynamics captured during steady state. We explore 3 total flow rates (brine flow rate + nitrogen flow rate): 0.1ml/min, 0.4ml/min, 0.7ml/min. With 3 fractional flows (brine flow rate / total flow rate) explored for each total flow rate: 0.85, 0.7 and 0.5. The images were captured with a voxel size of 2.75 µm3. In these data sets we observe the development of intermittent flow pathways, and the stability of these pathways when perturbed by a change in the flow rate .

en: The development and stability of intermittent fluid flow pathways during multiphase flow in porous media.


en:
We report a soft x-ray resonant magnetic scattering study of the spin configuration in multiferroic thin
films of Co0.975Ge0.025Cr2O4 (Ge-CCO) and CoCr2O4 (CCO) under low and high magnetic fields from 0.2 to
6.5 T. A characterization of Ge-CCO at a low magnetic field was performed, and the results were compared with
those of pure CCO. The ferrimagnetic phase transition temperature TC ≈ 95 K and the multiferroic transition
temperature TS ≈ 27 K in Ge-CCO are comparable with those observed in CCO. In Ge-CCO, the ordering wave
vector (qq0) observed below TS is slightly larger compared with that of CCO, and unlike CCO, the diffraction
intensity consists of two contributions that show a dissimilar x-ray polarization dependence. In Ge-CCO, the
coercive field observed at low temperatures was larger than the one reported for CCO. In both compounds,
an unexpected reversal of the spiral helicity, and therefore the electric polarization, was observed on simply
magnetic field cooling. In addition, we find a change in the helicity as a function of momentum transfer in the
magnetic diffraction peak of Ge-CCO, indicative of the presence of multiple magnetic spirals.

en: Raw and derived data set from the study: Magnetic field dependent cycloidal rotation in pristine and Ge-doped CoCr2O4


en: We identify a highly ordered Moiré lattice at the buried SrTiO3 (STO) - (La,Sr)(Al,Ta)-oxide (LSAT) interface by high-resolution X-ray diffraction reciprocal space mapping. We find long-ranged ordered Supercells of 106/107 unit cells of unstrained STO/LSAT, caused by complete lattice relaxation through high-temperature annealing. Transmission electron microscopy (TEM) images show that this periodicity is based on line dislocations at the interface region. The presence of such ordered Superstructures in such widely used complex oxides sets the ideal conditions for Moiré-tuned interfacial electronic modifications and ferroelectric Super-crystallinity, opening up the possibility for novel interface functionalities and impacting findings on vortex structured multilayers systems.

en: Buried Moiré Supercells through SrTiO3 nanolayer relaxation


en: Myelin insulates neuronal axons and enables fast signal transmission, constituting a key component of brain development, aging and disease. Yet, myelin-specific imaging of macroscopic samples remains a challenge. Here, we exploit myelin’s nanostructural periodicity, and use small-angle X-ray scattering tensor tomography (SAXS-TT) to simultaneously quantify myelin levels, nanostructural integrity and axon orientations in nervous tissue. Proof-of-principle is demonstrated in whole mouse brain, mouse spinal cord and human white and gray matter samples. Outcomes are validated by 2D/3D histology and compared to MRI measurements sensitive to myelin and axon orientations. Specificity to nanostructure is exemplified by concomitantly imaging different myelin types with distinct periodicities. Finally, we illustrate the method’s sensitivity towards myelin-related diseases by quantifying myelin alterations in dysmyelinated mouse brain. This non-destructive, stain-free molecular imaging approach enables quantitative studies of myelination within and across samples during development, aging, disease and treatment, and is applicable to other ordered biomolecules or nanostructures.

en: Nanostructure-specific X-ray tomography reveals myelin levels, integrity and axon orientations in mouse and human nervous tissue


en: Magma reservoirs are not directly accessible, limiting our capability to understand the prerequisites for an explosive eruption and our ability to perform experiments that simulate magmatic processes at depth. Therefore, deciphering volcanic precursors is key to forecasting volcanic eruptions. In the publication related to these datasets, we used synchrotron-based X-ray tomographic microscopy to observe felsic magma vesiculation at high temperature (1100 C) to establish the pre-eruptive conditions that favor explosive activity. Specifically, we studied the increase of seismic attenuation with increasing gas content during magma vesiculation.

en: The PSI Data Catalog is the central repository directory for scientific metadata generated at the Paul Scherrer Institut (PSI). Powered by SciCat—a community-driven, open-source metadata management framework co-developed by PSI—the catalog provides discoverability and standardized access pathways to petabyte-scale datasets produced across PSI’s large-scale research facilities, including the Swiss Light Source (SLS), the Swiss Spallation Neutron Source (SINQ), and the SwissFEL X-ray free-electron laser.

en: Felsic magma vesiculation revealed by synchrotron-based X-ray tomographic microscopy


en: The aim of this proposal is to image the complex vascular lesions seen in human pulmonary hypertension (PH). High resolution 3D image data can by itself, or when combined with subsequent sectioning and immunohistochemical analyses of the same specimen, create a detailed map of the distribution of pathology in 3D space. This project has the potential to advance our understanding of PH pathophysiology and increase our chances of finding relevant targets for drug development.

en: PSI Data Catalog

en:
Synchrotron Imaging of Complex Vascular Lesions in Human Pulmonary Hypertension:
Pathology Distribution in 3D Space


en:
In the original article associated with this dataset, we present synchrotron radiation-based X-ray phase-contrast imaging (X-PCI) as an efficient and non-destructive imaging technique to provide high resolution, three-dimensional (3D) information on myocardial microstructure in left ventricular hypertrophy. In the pilot study, the methodology was applied on tissue samples obtained from three patients that underwent septal myectomy. This technique allows for multi-scale investigation - to localize regions of interest, low resolution overlapping scans, at 5.8um effective pixel size, were achieved to cover the entire sample, whereas high resolution datasets, at 0.65 um pixel size, were collected locally allowing assessment of myocyte organization, 3D connective tissue distribution and vasculature.
X-PCI data was visualized and analyzed. 3D myocyte arrangement, interstitial fibrosis, collagen disarray, and vascular remodelling were identified and related to findings of non-invasive cardiac imaging. The integration of imaging data data illustrates the correspondence of macrostructural and functional non-invasive phenotypes with invasive microstructural phenotypes, suggesting the potential clinical utility of non-invasive myocardial deformation patterns in phenotyping left ventricular hypertrophy.

en: Etiology-Discriminative Multimodal Imaging of Left Ventricular Hypertrophy and Synchrotron-Based Assessment of Microstructural Tissue Remodeling

en: Environment


en:
Particle accelerators are enabling tools for scientific exploration and discovery in various disciplines.  Finding optimized operation points for these complex machines is a challenging task, however, due to the large number of parameters involved and the underlying non-linear dynamics. Here, we introduce two families of data-driven surrogate models, based on deep and invertible neural networks, that can replace the expensive physics computer models.
These models are employed in multi-objective optimisations to find Pareto optimal operation points for two fundamentally different types of particle accelerators. Our approach reduces the time-to-solution for a multi-objective accelerator optimisation up to a factor of 640 and the computational cost up to 98%. The framework established here should pave the way for future on-line and real-time multi-objective optimisation of particle accelerators.

en: Data for the paper: "Fast,  efficient  and  flexible  particle  accelerator  optimisation using densely connected and invertible neural networks"


en: Pump-probe experiment on antiferromagnetic Bragg peak

en: NaOsO3 magnetism SACLA XFEL experiment 2017/04


en:
We present a detailed low-energy muon spin rotation and x-ray magnetic circular dichroism (XMCD) investigation of the magnetic structure in ultrathin tetragonal (T)-CuO films. The measured muon-spin polarization decay indicates an antiferromagnetic (AFM) order with a transition temperature higher than 200 K. The XMCD signal obtained around the Cu L2,3 edges indicates the presence of pinned Cu
2+ moments that are parallel to the sample surface, and additionally, isotropic paramagnetic moments. The pinning of some of the Cu moments is caused by an AFM ordering consisting of moments that lie most likely in plane of the film. Moreover, pinned moments show a larger orbital magnetic moment contribution with an approximate ratio of m_orb/m_spin=1.5, indicating that these spins are located at sites with reduced symmetry. Some fractions of the pinned moments remain pinned from an AFM background even at 360 K, indicating that TN>360K. We propose a simple model that explains these experimental findings, showing that the magnetic order of the T-CuO ultrathin films differs from the theoretical predictions.

en: Magnetic order of tetragonal CuO ultrathin films


en: The associated article to these datasets describes a new genus and species, Skyttegaardia galtieri E.M.Friis, P.R.Crane & E.M.Friis. The fossils were isolated from dark clay of the early-mid Berriasian Skyttegård Member of the Rabekke Formation, collected at the Skyttegård and Arnager Bay localities, Bornholm, Denmark. The fossils were studied using SEM. Internal structures of the fossils were also investigated using synchrotron radiation X-ray tomographic microscopy at the TOMCAT Beamline, Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland. The new taxon is based on small microsporangiophores consisting of a proximal fertile portion and a distal sterile extension. The fertile portion is stalk-like with two sporangia deeply sunken into two cavities in the presumed abaxial surface. The sterile distal tip is long, horn-shaped and tapers to a slender point. Pollen grains in situ are of the Monosulcites/Cycadopites type, monocolpate, tectate-psilate. General organisation and details of epidermal features, as well as pollen morphology, are consistent with a possible relationship of Skyttegaardia galtieri to extant Cycadales. However, in the low number of partially embedded sporangia Skyttegaardia is distinct from the microsporophores of extant cycads, in which the sporangia are usually crowded on the surface of the microsporangiophores, typically in groups of two to five.

en: Synchrotron radiation X-ray tomographic microscopy datasets for a putative cycad from the earliest Cretaceous (Berriasian) of the isle of Bornholm, Denmark


en: Absorption spectra of optical transitions of Ho and Tb ions in LiYF4 were taken with different experimental techniques (e.g. FTIR, TDS, EPR and UTC) and ranging from MW, through THz, IR and visible, as part of Adrian Beckert's PhD thesis.

en: LiYF4:Ho and LiYF4:Tb data measured by Adrian Beckert


en: THz FTIR spectroscopy on LiYF4:Tm

en: The PSI Data Catalog is the central repository directory for scientific metadata generated at the Paul Scherrer Institut (PSI). Powered by SciCat—a community-driven, open-source metadata management framework co-developed by PSI—the catalog provides discoverability and standardized access pathways to petabyte-scale datasets produced across PSI’s large-scale research facilities, including the Swiss Light Source (SLS), the Swiss Spallation Neutron Source (SINQ), and the SwissFEL X-ray free-electron laser.


en: Quantum sensors and qubits are usually two-level systems (TLS), the quantum analogues of classical bits assuming binary values 0 or 1. They are useful to the extent to which superpositions of 0 and 1 persist despite a noisy environment. The standard prescription to avoid decoherence of solid-state qubits is their isolation by means of extreme dilution in ultrapure materials. We demonstrate a different strategy using the rare-earth insulator LiY1−xTbxF4 (x = 0.001) which realizes a dense random network of TLS. Some TLS belong to strongly interacting Tb3+ pairs whose quantum states, thanks to localization effects, form highly coherent qubits with 100-fold longer coherence times than single ions. Our understanding of the underlying decoherence mechanisms—and of their suppression—suggests that coherence in networks of dipolar coupled TLS can be enhanced rather than reduced by the interactions.

en: PSI Data Catalog

en: LiYF4:Tb Absorption and EPR spectroscopy


en:
FTIR at PSI
TDS at Leeds
UTC absorption spectroscopy at UCL

The insulating rare-earth magnet LiY1−xHoxF4 has received great attention because a laboratory field applied perpendicular to its crystallographic caxis converts the low-energy electronic spin Hamiltonian into the (dilute) transverse field Ising model. The mapping between the real magnet and the transverse field Ising model is strongly dependent on the exact nature of the low-energy Hamiltonian for the material, which can be determined by spectroscopy in the dilute limit. The energies of the eigenstates are in the difficult terahertz (THz) regime, and here we use THz time domain and Fourier transform spectroscopy to directly measure the lowest crystal-field levels of LiY1−xHoxF4 in the dilute limit, including nuclear hyperfine substructure. The high resolution of our measurements allows us to observe the nonequidistantly spaced Ho (I=72) hyperfine transitions originating from dipolar and quadrupolar hyperfine interactions. We provide refined crystal-field parameters and extract the dipolar and quadrupolar hyperfine constants AJ=0.02703$\pm$0.00003 cm−1 (810.3$\pm$0.9 MHz) and B=0.04$\pm$0.01 cm−1(1.2$\pm$0.3 GHz), respectively. Thereupon we determine all crystal-field energy levels and magnetic moments of the 5I8 ground-state manifold, including the (nonlinear) hyperfine corrections. The latter improve the prediction precision by a factor of 60 compared to previous crystal-field parameters. Additionally, we establish the far-infrared, low-temperature refractive index of LiY1−xHoxF4.

en: LiYHoF4 absorption spectroscopy


en: The article accompanying this dataset gives a brief overview of the recent developments of time-resolved X-ray tomography that have led to what we now call “tomoscopy”. A novel setup is presented and applied that pushes temporal resolution down to just 1 ms, i.e. 1000 tomograms per second (‘tps') are acquired, while maintaining spatial resolutions of micrometres and running experiments for minutes without interruption. Applications recorded at different acquisition rates ranging from 50 to 1000 tps are presented. We observe and quantify the immiscible hypermonotectic reaction of AlBi10 (in wt%) alloy and dendrite evolution in AlGe10 (in wt%) casting alloy during fast solidification. We analyse the combustion process and the evolution of the constituents in a burning sparkler. Finally, we follow the structure and density of two metal foams over a long period of time and derive details of bubble formation and bubble ageing including quantitative analyses of bubble parameters with millisecond temporal resolution.

en: Tomoscopy: Time-resolved tomography for dynamic processes in materials

en: Environment


en: X-ray scattering tensor tomography (XSTT) facilitates the investigation of microstructural organization in statistically large sample volumes. Leveraging recent developments of diffractive optics, orders of magnitude faster XSTT has been developed and demonstrated. This new rapid acquisition method unlocks XSTT applications for rapid inspections and time-resolved studies of microstructure over orders of magnitude bigger volumetric field of views.

en: X-ray scattering tensor tomography data for a validation sample


en: The associated article to these datasets describes a new genus and two new species from the Late Cretaceous (Campanian-Maastrichtian) Mira locality, District of Coimbra, Portugal. The new taxa are based on small lignitized and charcoalified flower buds, post-anthetic flowers and a fruit. Internal structures of the fossils were investigated using synchrotron radiation X-ray tomographic microscopy at the TOMCAT Beamline, Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland. Internal structures and other details provide clear evidence for a phylogenetic position of the fossils in the family Primulaceae of the order Ericales. A key distinctive feature that is critical for placing the fossils in the Primulaceae s. l., is the free, central dome-shaped placenta that bears numerous, densely spaced ovules. The fruit matured into a capsule containing many, minute, reticulate seeds. Phylogenetic analyses using external and internal features of the fossils confirm their relationship to Primulaceae s. l. and indicate a position as sister to the genus Samolus of the subfamily Theophrastoideae. The occurrence of these fossils in the Late Cretaceous calls into question a previous hypothesis that the Theophrastoideae originated in the Neotropics and dispersed relatively recently into other regions.

en: Synchrotron radiation X-ray tomographic microscopy datasets for primuloid flowers from the Late Cretaceous of Portugal


en:
Ptychographic hard X-ray computed tomography (PXCT) is a recent method allowing imaging with quantitative electron-density contrast. Here, we imaged at cryogenic temperature and without sectioning, cellular and subcellular structures of a chemically-fixed and stained wild-type mouse retina (tomogram 1), including axons and synapses with complete isotropic 3D information over tens of microns. Comparison with tomograms of degenerative retina from a mouse model of retinitis pigmentosa (tomogram 2) illustrates the potential of this method for analysing disease processes like neurodegeneration at sub-200 nm resolution.

As a non-destructive imaging method, PXCT is very suitable for correlative imaging. Within the outer plexiform layer containing the photoreceptors synapses, we identified somatic synapses. We used a small region inside the X-ray-imaged sample for further high-resolution focused ion beam / scanning electron microscope (FIB/SEM) tomography (tomogram 3). The subcellular structures of synapses obtained with the X-ray technique matched the EM data demonstrating that PXCT is a powerful scanning method for tissue volumes of more than 60 cells and sensitive enough for identification of regions as small as 200 nm, remaining available for further structural and biochemical investigations.

en: retina electron sem ptychography neurodegeneration synapse pigmentosa hard mouse x-ray tomography retinitis photoreceptors neurobiology

en: Imaging of retina cellular and subcellular structures using ptychographic hard X-ray tomography.

electron

display_name: electron

hard

display_name: hard

mouse

display_name: mouse

neurobiology

display_name: neurobiology

neurodegeneration

display_name: neurodegeneration

photoreceptors

display_name: photoreceptors

pigmentosa

display_name: pigmentosa

ptychography

display_name: ptychography

retina

display_name: retina

retinitis

display_name: retinitis

sem

display_name: sem

synapse

display_name: synapse

tomography

display_name: tomography

x-ray

display_name: x-ray