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At least 1,099 records · Page 61
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Rb3Pd by Materials Project

Rb4PdRb8Pd3 crystallizes in the tetragonal I4/mmm space group. The structure is two-dimensional and consists of two Rb4Pd clusters and two Rb8Pd3 sheets oriented in the (0, 0, 1) direction. In each Rb4Pd cluster, Rb is bonded in a single-bond geometry to one Pd atom. The Rb–Pd bond length is 3.16 Å. Pd is bonded in a square co-planar geometry to four equivalent Rb atoms. In each Rb8Pd3 sheet, Rb is bonded in a water-like geometry to two Pd atoms. There are one shorter (3.56 Å) and one longer (3.72 Å) Rb–Pd bond lengths. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a body-centered cubic geometry to eight equivalent Rb atoms. In the second Pd site, Pd is bonded in a 4-coordinate geometry to four equivalent Rb atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CoC4(NCl2)2 by Materials Project

CoCl4(C2N)2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four C2N clusters and four CoCl4 clusters. In each C2N cluster, there are four inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a distorted single-bond geometry to one C2+ and one N3- atom. The C–C bond length is 1.22 Å. The C–N bond length is 1.30 Å. In the second C2+ site, C2+ is bonded in a distorted linear geometry to one C2+ and one N3- atom. The C–N bond length is 1.30 Å. In the third C2+ site, C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.20 Å. In the fourth C2+ site, C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.20 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a linear geometry to two C2+ atoms. In the second N3- site, N3- is bonded in a linear geometry to two C2+ atoms. In each CoCl4 cluster, Co2+ is bonded in a tetrahedral geometry to four Cl1- atoms. There are two shorter (2.13 Å) and two longer (2.14 Å) Co–Cl bond lengths. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Co2+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Co2+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Co2+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Co2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on N3Cl by Materials Project

ClN3 crystallizes in the orthorhombic Cmc2_1 space group. The structure is zero-dimensional and consists of four ClN3 clusters. there are three inequivalent N+0.33+ sites. In the first N+0.33+ site, N+0.33+ is bonded in a water-like geometry to one N+0.33+ and one Cl1- atom. The N–N bond length is 1.25 Å. The N–Cl bond length is 1.75 Å. In the second N+0.33+ site, N+0.33+ is bonded in a distorted linear geometry to two N+0.33+ atoms. The N–N bond length is 1.15 Å. In the third N+0.33+ site, N+0.33+ is bonded in a single-bond geometry to one N+0.33+ atom. Cl1- is bonded in a single-bond geometry to one N+0.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ReClO3 by Materials Project

ReO3Cl is Iron carbide-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four ReO3Cl clusters. Re7+ is bonded in a tetrahedral geometry to three O2- and one Cl1- atom. There is one shorter (1.72 Å) and two longer (1.73 Å) Re–O bond length. The Re–Cl bond length is 2.23 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. Cl1- is bonded in a single-bond geometry to one Re7+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HgClO4 by Materials Project

HgOClO3 crystallizes in the orthorhombic Pbcm space group. The structure is one-dimensional and consists of four ClO3 clusters and two HgO ribbons oriented in the (0, 1, 0) direction. In each ClO3 cluster, there are two inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Cl atom. The O–Cl bond length is 1.50 Å. In the second O site, O is bonded in a single-bond geometry to one Cl atom. The O–Cl bond length is 1.48 Å. Cl is bonded in a trigonal non-coplanar geometry to three O atoms. In each HgO ribbon, Hg is bonded in a linear geometry to two equivalent O atoms. Both Hg–O bond lengths are 2.02 Å. O is bonded in a bent 120 degrees geometry to two equivalent Hg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AlH18Ru(NF)6 by Materials Project

Ru(NH3)6AlF6 is Halite, Rock Salt structured and crystallizes in the cubic Pa-3 space group. The structure is zero-dimensional and consists of four AlF6 clusters and four Ru(NH3)6 clusters. In each AlF6 cluster, Al3+ is bonded in an octahedral geometry to six equivalent F1- atoms. All Al–F bond lengths are 1.84 Å. F1- is bonded in a single-bond geometry to one Al3+ atom. In each Ru(NH3)6 cluster, Ru3+ is bonded in an octahedral geometry to six equivalent N3- atoms. All Ru–N bond lengths are 2.12 Å. N3- is bonded in a distorted trigonal non-coplanar geometry to one Ru3+ and three H1+ atoms. All N–H bond lengths are 1.03 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ga2PdBr8 by Materials Project

PdGa2Br8 crystallizes in the monoclinic C2/m space group. The structure is zero-dimensional and consists of two PdGa2Br8 clusters. Pd2+ is bonded in a square co-planar geometry to four equivalent Br1- atoms. All Pd–Br bond lengths are 2.47 Å. Ga3+ is bonded in a tetrahedral geometry to four Br1- atoms. There are a spread of Ga–Br bond distances ranging from 2.29–2.46 Å. There are three inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in an L-shaped geometry to one Pd2+ and one Ga3+ atom. In the second Br1- site, Br1- is bonded in a single-bond geometry to one Ga3+ atom. In the third Br1- site, Br1- is bonded in a single-bond geometry to one Ga3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on As2Se2S(NF6)2 by Materials Project

N2Se2S(AsF6)2 crystallizes in the monoclinic C2 space group. The structure is zero-dimensional and consists of eight AsF6 clusters and four N2Se2S clusters. In each AsF6 cluster, As5+ is bonded in an octahedral geometry to six F1- atoms. There are a spread of As–F bond distances ranging from 1.76–1.81 Å. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the third F1- site, F1- is bonded in a distorted single-bond geometry to one As5+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the sixth F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In each N2Se2S cluster, there are two inequivalent N4+ sites. In the first N4+ site, N4+ is bonded in a bent 120 degrees geometry to one Se2- and one S2- atom. The N–Se bond length is 1.74 Å. The N–S bond length is 1.59 Å. In the second N4+ site, N4+ is bonded in a bent 120 degrees geometry to one Se2- and one S2- atom. The N–Se bond length is 1.74 Å. The N–S bond length is 1.59 Å. Se2- is bonded in a 1-coordinate geometry to one N4+ atom. S2- is bonded in a distorted water-like geometry to two N4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgSeO9 by Materials Project

MgO6SeO3 crystallizes in the trigonal R3 space group. The structure is three-dimensional and consists of three SeO3 clusters and one MgO6 framework. In each SeO3 cluster, Se is bonded in a trigonal planar geometry to three equivalent O atoms. All Se–O bond lengths are 1.63 Å. O is bonded in a single-bond geometry to one Se atom. In the MgO6 framework, Mg is bonded in an octahedral geometry to six O atoms. All Mg–O bond lengths are 2.20 Å. There are two inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one Mg and one O atom. The O–O bond length is 1.28 Å. In the second O site, O is bonded in a distorted bent 120 degrees geometry to one Mg and one O atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AlBr3N by Materials Project

AlNBr3 is Silicon tetrafluoride-derived structured and crystallizes in the orthorhombic Pbca space group. The structure is zero-dimensional and consists of sixteen AlNBr3 clusters. Al is bonded in a trigonal pyramidal geometry to one N and three Br atoms. The Al–N bond length is 2.02 Å. There are one shorter (2.27 Å) and two longer (2.29 Å) Al–Br bond lengths. N is bonded in a single-bond geometry to one Al atom. There are three inequivalent Br sites. In the first Br site, Br is bonded in a single-bond geometry to one Al atom. In the second Br site, Br is bonded in a single-bond geometry to one Al atom. In the third Br site, Br is bonded in a single-bond geometry to one Al atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Atomic structure and Mott nature of the insulating charge density wave phase of 1T-TaS 2

Here, using x-ray pair distribution function (PDF) analysis and computer modeling, we explore structure models for the complex charge density wave (CDW) phases of layered 1T-TaS 2 that both well capture their atomic-level features and are amenable to electronic structure calculations. The models give the most probable position of constituent atoms in terms of 3D repetitive unit cells comprising a minimum number of Ta–S layers. Structure modeling results confirm the emergence of star-of-David (SD) like clusters of Ta atoms in the high-temperature incommensurate (IC) CDW phase and show that, contrary to the suggestions of recent studies, the low-temperature commensurate (C) CDW phase expands upon cooling thus reducing lattice strain. The C-CDW phase is also found to preserve the stacking sequence of Ta–S layers found in the room temperature, nearly commensurate (NC) CDW phase to a large extent. DFT based on the PDF refined model shows that bulk C-CDW 1T-TaS 2 also preserves the insulating state of individual layers of SD clusters, favoring the Mott physics description of the metal-to-insulator (NC-CDW to C-CDW) phase transition in 1T-TaS 2 . Our work highlights the importance of using precise crystal structure models in determining the nature of electronic phases in complex materials.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2022

Residual mean field model of valence quarks in the nucleon

Abstract We develop a non-perturbative model for valence parton distribution functions (PDFs) based on the mean field interactions of valence quarks in the nucleonic interior. The main motivation for the model is to obtain a mean field description of the valence quarks as a baseline to study the short range quark–quark interactions that generate the high x tail of PDFs. The model is based on the separation of the valence three-quark cluster and residual system in the nucleon. Then the nucleon structure function is calculated within the effective light-front diagrammatic approach introducing nonperturbative light-front valence quark and residual wave functions. Within the model a new relation is obtained between the position, $$x_p$$ x p , of the peak of $$xq_V(x)$$ x q V ( x ) distribution of the valence quark and the effective mass of the residual system, $$m_R$$ m R , in the form: $$x_{p} \approx {1\over 4} (1-{m_R\over m_N})$$ x p ≈ 1 4 ( 1 - m R m N ) at starting $$Q^2$$ Q 2 . This relation explains the difference in the peak positions for d- and u-quarks through the expected difference of residual masses for valence d- and u-quark distributions. The parameters of the model are fixed by fitting the calculated valence quark distributions to the phenomenological PDFs. This allowed us to estimate the overall mean field contribution in baryonic and momentum sum rules for valence d- and u-quarks. Finally, the evaluated parameters of the non-perturbative wave functions of valence 3q-cluster and residual system can be used in calculation of other quantities such as nucleon form factors, generalized partonic and transverse momentum distributions.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2024

Vapor Phase Infiltration of Titanium Oxide into P3HT to Create Organic–Inorganic Hybrid Photocatalysts

Herein, we report for the first time the use of vapor phase infiltration (VPI) to infuse conducting polymers with inorganic metal oxide clusters that together form a photocatalytic material. While vapor infiltration has previously been used to electrically dope conjugated polymers, this is the first time, to our knowledge, that the resultant hybrid material has been demonstrated to have photocatalytic properties. The system studied is poly(3-hexylthiophene-2,5-diyl) (P3HT) vapor infiltrated with TiCl 4 and H 2 O to create P3HT-TiO x organic–inorganic hybrid photocatalytic materials. X-ray photoelectron spectroscopy analysis shows that P3HT-TiO x VPI films consist of a partially oxidized P3HT matrix, and the infiltrated titanium inorganic is in a 4+ oxidation state with mostly oxide coordination. Upon visible light illumination, these P3HT-TiO x hybrids degrade methylene blue dye molecules. The P3HT-TiO x hybrids are 4.6× more photocatalytically active than either the P3HT or TiO 2 individually or when sequentially deposited (e.g., P3HT on TiO 2 ). On a per surface area basis, these hybrid photocatalysts are comparable or better than other best in class polymer semiconductor photocatalysts. VPI of TiCl 4 + H 2 O into P3HT makes a unique hybrid structure and idealized photocatalyst architecture by creating nanoscale TiO x clusters concentrated toward the surface achieving extremely high catalytic rates. The mechanism for this enhanced photocatalytic rate is understood using photoluminescence spectroscopy, which shows significant quenching of excitons in P3HT-TiO x as compared to neat P3HT, indicating that P3HT acts as a photosensitizer for the TiO x catalyst sites in the hybrid material. This work introduces a new approach to designing and synthesizing organic–inorganic hybrid photocatalytic materials, with expansive opportunities for further exploration and optimization.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on ReCl3O2 by Materials Project

ReO2Cl3 is Tungsten structured and crystallizes in the orthorhombic Pnnm space group. The structure is zero-dimensional and consists of two ReO2Cl3 clusters. Re7+ is bonded in a 2-coordinate geometry to two equivalent O2- and four Cl1- atoms. Both Re–O bond lengths are 1.71 Å. There are two shorter (2.29 Å) and two longer (2.62 Å) Re–Cl bond lengths. O2- is bonded in a single-bond geometry to one Re7+ atom. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Re7+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Re7+ atom. In the third Cl1- site, Cl1- is bonded in a water-like geometry to two equivalent Re7+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ClOF3 by Materials Project

OClF3 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four OClF3 clusters. In two of the OClF3 clusters, O is bonded in a single-bond geometry to one Cl atom. The O–Cl bond length is 1.41 Å. Cl is bonded in a see-saw-like geometry to one O and three F atoms. There are a spread of Cl–F bond distances ranging from 1.67–1.88 Å. There are three inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one Cl atom. In the second F site, F is bonded in a single-bond geometry to one Cl atom. In the third F site, F is bonded in a single-bond geometry to one Cl atom. In two of the OClF3 clusters, O is bonded in a single-bond geometry to one Cl atom. The O–Cl bond length is 1.41 Å. Cl is bonded in a see-saw-like geometry to one O and three F atoms. There are a spread of Cl–F bond distances ranging from 1.67–1.83 Å. There are three inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one Cl atom. In the second F site, F is bonded in a single-bond geometry to one Cl atom. In the third F site, F is bonded in a single-bond geometry to one Cl atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Si3Au10 by Materials Project

Au10Si3 is Tungsten structured and crystallizes in the cubic I-43m space group. The structure is zero-dimensional and consists of two Au10Si3 clusters. there are three inequivalent Au+0.40- sites. In the first Au+0.40- site, Au+0.40- is bonded in a trigonal non-coplanar geometry to three equivalent Si+1.33+ atoms. All Au–Si bond lengths are 2.58 Å. In the second Au+0.40- site, Au+0.40- is bonded in a distorted single-bond geometry to one Si+1.33+ atom. The Au–Si bond length is 2.54 Å. In the third Au+0.40- site, Au+0.40- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Si+1.33+ atoms. All Au–Si bond lengths are 2.62 Å. Si+1.33+ is bonded in a 8-coordinate geometry to six Au+0.40- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Neutrons in Structural Biology: Challenges and Opportunities (Workshop Report)

Gaining a thorough understanding of biological systems requires building our knowledge about biological processes from the level of atoms and electrons, and up to whole organisms. Such comprehensive knowledge will allow for a predictive understanding of complex biological systems behavior. It will guide us in the design and development of novel therapeutics and vaccines to tackle existing health threats and to prepare for future pandemics, and it will provide information necessary to create new biomaterials and bio-inspired technologies through manipulation of biological macromolecules, their assemblies, single cells and even microorganisms. Reaching these goals will require a synergistic combination of multiple experimental techniques with molecular calculations and predictive simulations, and the design and development of new techniques and capabilities that bridge current knowledge and technology gaps. Neutron scattering provides unique information about the biomacromolecular structure and function and can play a major role in achieving these goals. A workshop was held to engage the scientific community in identifying pressing challenges in biochemistry, structural biology, enzymology and structure-guided drug design not solved with the current neutron scattering technologies or utilizing other structural biology techniques such as X-ray crystallography, NMR, and cryo-EM. The workshop brought together structural biology, biochemistry and computational experts, as well as early career researchers and students, creating a forum for discussing scientific advancement and collaboration. The workshop included a one-day satellite training workshop where graduate students and postdoctoral researchers were educated in the application of neutron crystallography and small-angle scattering in structural biology. Furthermore, the Instrument Scientific Advisory Board (ISAB) for the development of a macromolecular neutron diffractometer at ORNL’s Second Target Station was introduced at the workshop. The major outcome was that neutrons can provide atomic-level understanding of biomacromolecular structure, function and dynamics which is of paramount importance for addressing the identified challenges. Neutron crystallography, in particular, can resolve long-standing biochemical issues regarding enzyme function by delineating the underlying chemistry and can have a major impact on the design of small-molecule therapeutics, especially in combination with molecular computation (quantum chemistry and molecular dynamics simulations) and the emerging artificial intelligence (AI)-assisted drug design technologies. The unique properties of neutrons, including their high sensitivity to hydrogen and their non-destructive nature, make them ideal probes of biological matter. There is a palpable need in the scientific community to expand and enhance the impact of neutron sciences on biology. Neutron crystallography is the only structural biology method capable of determining positions of all hydrogen atoms in proteins, nucleic acids and their complexes at near-physiological temperatures and of unstable species at cryogenic temperatures. Moreover, neutron analysis is non-ionizing, non-destructive and does not perturb the structure or redox chemistry of active site metal centers and clusters in proteins, which can be invaluable for studying radiation-sensitive metalloprotein complexes. Further, neutron energies used in scattering applications are similar to atomic motions, permitting neutron spectroscopies to characterize the dynamics of biomacromolecules on the picosecond to microsecond timescales. The different sensitivities of neutrons to protium (H) and deuterium (D) isotopes of hydrogen allow enhanced visibility of specific parts of biological complexes through isotopic labeling. The impact of neutrons will be most powerful when neutron scattering is combined with complementary experimental techniques that use photons and electrons, and with high-performance computing. The interconnection and mutuality of the experimental and theoretical capabilities will drive discoveries in biological and health sciences to generate more complete picture of complex biological systems. The major limitation in the field of biological neutron crystallography has been signal-to-noise, demanding large samples that are difficult to produce for the majority of biomacromolecules and limiting the applicability of this technique in biological sciences. A neutron crystallography instrument at the Second Target Station will revolutionize biological science with neutrons by engaging a large scientific community of structural biologists, enabling successful neutron diffraction experiments from radically smaller biomacromolecular crystals, resolving unanswered biochemical questions, and meaningfully contributing to rational drug design. The meeting highlighted 10 grand challenges that will be addressed with this advanced capability over the next decade and beyond, and the recommendations required to help address them are given below.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Materials Data on NbP2NCl12 by Materials Project

NbCl6P2NCl6 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of four NbCl6 clusters and four P2NCl6 clusters. In each NbCl6 cluster, Nb5+ is bonded in an octahedral geometry to six Cl1- atoms. There are a spread of Nb–Cl bond distances ranging from 2.38–2.40 Å. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Nb5+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Nb5+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Nb5+ atom. In each P2NCl6 cluster, P5+ is bonded to one N3- and three Cl1- atoms to form corner-sharing PNCl3 tetrahedra. The P–N bond length is 1.56 Å. There are a spread of P–Cl bond distances ranging from 1.97–1.99 Å. N3- is bonded in a bent 150 degrees geometry to two equivalent P5+ atoms. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one P5+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one P5+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one P5+ atom.

36 MATERIALS SCIENCE↗