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At least 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on HI3 by Materials Project

HI3 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of two HI3 clusters. H is bonded in a single-bond geometry to one I atom. The H–I bond length is 1.65 Å. There are three inequivalent I sites. In the first I site, I is bonded in a 2-coordinate geometry to one I atom. The I–I bond length is 2.72 Å. In the second I site, I is bonded in a single-bond geometry to one H and one I atom. The I–I bond length is 3.45 Å. In the third I site, I is bonded in a bent 150 degrees geometry to two I atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RuSN4(ClO)2 by Materials Project

RuN2ClN2ClSO2 crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of four sulfur dioxide molecules, four N2Cl clusters, and four RuN2Cl clusters. In each N2Cl cluster, N1+ is bonded in a single-bond geometry to one Cl1- atom. The N–Cl bond length is 1.53 Å. Cl1- is bonded in a 2-coordinate geometry to two equivalent N1+ atoms. In each RuN2Cl cluster, Ru4+ is bonded in a trigonal non-coplanar geometry to two equivalent N1+ and one Cl1- atom. Both Ru–N bond lengths are 1.72 Å. The Ru–Cl bond length is 2.26 Å. N1+ is bonded in a single-bond geometry to one Ru4+ atom. Cl1- is bonded in a single-bond geometry to one Ru4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe3WC14(SO7)2 by Materials Project

WFe3C9S2O9(CO)5 crystallizes in the monoclinic C2/m space group. The structure is zero-dimensional and consists of twenty formaldehyde molecules and four WFe3C9S2O9 clusters. In each WFe3C9S2O9 cluster, W6+ is bonded in a single-bond geometry to one S2- atom. The W–S bond length is 2.54 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to three C+1.21+ and two S2- atoms to form distorted edge-sharing FeC3S2 trigonal bipyramids. There is two shorter (1.78 Å) and one longer (1.81 Å) Fe–C bond length. There are one shorter (2.27 Å) and one longer (2.30 Å) Fe–S bond lengths. In the second Fe3+ site, Fe3+ is bonded to three C+1.21+ and two S2- atoms to form distorted edge-sharing FeC3S2 square pyramids. There are a spread of Fe–C bond distances ranging from 1.78–1.83 Å. There are one shorter (2.24 Å) and one longer (2.26 Å) Fe–S bond lengths. There are five inequivalent C+1.21+ sites. In the first C+1.21+ site, C+1.21+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C+1.21+ site, C+1.21+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.21+ site, C+1.21+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the fourth C+1.21+ site, C+1.21+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fifth C+1.21+ site, C+1.21+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to one W6+ and three Fe3+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three Fe3+ atoms. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.21+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.21+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.21+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.21+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one C+1.21+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sb4OsC6(O3F11)2 by Materials Project

Os(CO)6(Sb2F11)2 is T-50 Boron-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two Os(CO)6 clusters and four Sb2F11 clusters. In each Os(CO)6 cluster, Os2- is bonded in an octahedral geometry to six C4+ atoms. All Os–C bond lengths are 2.02 Å. There are three inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a distorted single-bond geometry to one Os2- and one O2- atom. The C–O bond length is 1.14 Å. In the second C4+ site, C4+ is bonded in a distorted single-bond geometry to one Os2- and one O2- atom. The C–O bond length is 1.14 Å. In the third C4+ site, C4+ is bonded in a distorted linear geometry to one Os2- and one O2- atom. The C–O bond length is 1.14 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C4+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C4+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C4+ atom. In each Sb2F11 cluster, there are two inequivalent Sb3+ sites. In the first Sb3+ site, Sb3+ is bonded to six F1- atoms to form corner-sharing SbF6 octahedra. The corner-sharing octahedral tilt angles are 33°. There are a spread of Sb–F bond distances ranging from 1.89–2.06 Å. In the second Sb3+ site, Sb3+ is bonded to six F1- atoms to form corner-sharing SbF6 octahedra. The corner-sharing octahedral tilt angles are 33°. There are a spread of Sb–F bond distances ranging from 1.89–2.11 Å. There are eleven inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the fifth F1- site, F1- is bonded in a bent 150 degrees geometry to two Sb3+ atoms. In the sixth F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the seventh F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the eighth F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the ninth F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the tenth F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the eleventh F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N by Materials Project

C3N crystallizes in the tetragonal P4/mmm space group. The structure is one-dimensional and consists of eight methane molecules; two tetramethylammonium molecules; one C2N ribbon oriented in the (0, 0, 1) direction; and two CN ribbons oriented in the (0, 0, 1) direction. In the C2N ribbon, C1+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.46 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a square co-planar geometry to four equivalent C1+ and two equivalent N3- atoms. Both N–N bond lengths are 2.46 Å. In the second N3- site, N3- is bonded in a linear geometry to two equivalent N3- atoms. In each CN ribbon, C1+ is bonded in a linear geometry to two equivalent N3- atoms. Both C–N bond lengths are 1.23 Å. N3- is bonded in a linear geometry to two equivalent C1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Developing Reaction Chemistry Models from Reactive Molecular Dynamics: TATB

Reactive Molecular Dynamic (RMD) are used to simulate the cook-off chemistry of TATB at a variety of fixed density and fixed temperature conditions. The chemical transformations are monitored using a Coordination Geometry Analysis (CGA) approach which tracks which atom types are bonded to each specific atom. This particularly identifies oxidation state changes that occur during the transformations. Correlations between these different chemical changes are identified using a Non-negative Matrix Factorization (NMF) approach. These identify reduced order chemistry models for the TATB system which contains six components whose concentration profiles are a function of both the temperature and density/pressure. The time histories of these transformations appear to show exponential growth/decay properties that could be fit with Arrhenius rates. These components should form the basis of deflagration rate models for these materials which could then be used in mesoscale simulations to analyze accidental initiation, shock-to-detonation and detonation propagation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Mapping 1D Confined Electromagnetic Edge States in 2D Monolayer Semiconducting MoS 2 Using 4D-STEM

Here, four-dimensional (4D) scanning transmission electron microscopy is used to study the electric fields at the edges of 2D semiconducting monolayer MoS2. Sub-nanometer 1D features in the 2D electric field maps are observed at the outermost region along zigzag edges and also along nanowire MoS-terminated MoS 2 edges. Atomic-scale oscillations are detected in the magnitude of the 1D electromagnetic edge state, with spatial variations that depend on the specific periodic edge reconstructions. Electric field reconstructions, along with integrated differential phase contrast reconstructions, reveal the presence of low Z number atoms terminating many of the uniform edges, which are difficult to detect by annular dark field scanning transmission electron microscopy due to its limited dynamic range. Density functional theory calculations support the formation of periodic 1D edge states and also show that enhancement of the electric field magnitude can occur for some edge terminations. The experimentally observed electric fields at the edges are attributed to the absence of an opposing electric field from a nearest neighbor atom when the electron beam propagates through the 2D monolayer and interacts. These results show the potential of 4D-STEM to map the atomic scale structure and fluctuations of electric fields around edge atoms with different bonding states than bulk atoms in 2D materials, beyond conventional imaging.

2D materials↗
NASA NTRS1974

Preparation of thick molybdenum targets

Thick natural molybdenum deposits on nickel plated copper substrates were prepared by thermal decomposition of molybdenum hexacarbonyl vapors on a heated surface in an inert gas atmosphere. The molybdenum metal atoms are firmly bonded to the substrate atoms, thus providing an excellent thermal contact across the junction. Molybdenum targets thus prepared should be useful for internal bombardment in a cyclotron where thermal energy inputs can exceed 10 kW.

Singh, J. J.↗
DOE OSTI2020

Materials Data on HW2C9NO10 by Materials Project

W2HW2H(NO)2(CO)18 crystallizes in the monoclinic C2 space group. The structure is zero-dimensional and consists of thirty-six formaldehyde molecules, two W2H clusters, and two W2H(NO)2 clusters. In each W2H cluster, W5+ is bonded in a single-bond geometry to one H1+ atom. The W–H bond length is 1.92 Å. H1+ is bonded in a bent 120 degrees geometry to two equivalent W5+ atoms. In each W2H(NO)2 cluster, W5+ is bonded in a linear geometry to one N3- and one H1+ atom. The W–N bond length is 1.90 Å. The W–H bond length is 1.95 Å. N3- is bonded in a linear geometry to one W5+ and one O2- atom. The N–O bond length is 1.17 Å. H1+ is bonded in a bent 120 degrees geometry to two equivalent W5+ atoms. O2- is bonded in a single-bond geometry to one N3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AgS8N9(ClO6)2 by Materials Project

(NAgN)2N2(NS2)4(N2Cl)4(SO3)8 crystallizes in the tetragonal I-42d space group. The structure is zero-dimensional and consists of four ammonia molecules, sixteen sulfur trioxide molecules, eight N2Cl clusters, four NAgN clusters, and eight NS2 clusters. In each N2Cl cluster, N+4.56+ is bonded in a single-bond geometry to one Cl1- atom. The N–Cl bond length is 1.50 Å. Cl1- is bonded in a distorted bent 150 degrees geometry to two equivalent N+4.56+ atoms. In each NAgN cluster, Ag1+ is bonded in a distorted linear geometry to two equivalent N+4.56+ atoms. Both Ag–N bond lengths are 2.07 Å. N+4.56+ is bonded in a single-bond geometry to one Ag1+ atom. In each NS2 cluster, N+4.56+ is bonded in a linear geometry to two equivalent S2- atoms. Both N–S bond lengths are 1.53 Å. S2- is bonded in a distorted single-bond geometry to one N+4.56+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on B4PF9 by Materials Project

BPF3(BF2)3 is Magnesium tetraboride-derived structured and crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of twelve difluoroborane molecules and four BPF3 clusters. In each BPF3 cluster, B3+ is bonded in a single-bond geometry to one P3- atom. The B–P bond length is 1.85 Å. P3- is bonded in a 4-coordinate geometry to one B3+ and three F1- atoms. All P–F bond lengths are 1.55 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one P3- atom. In the second F1- site, F1- is bonded in a single-bond geometry to one P3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sb3Au2Xe2F19 by Materials Project

Xe2Au2Sb3F19 crystallizes in the triclinic P-1 space group. The structure is one-dimensional and consists of one Xe2Au2Sb3F19 ribbon oriented in the (0, 1, 1) direction. Xe is bonded in a single-bond geometry to one Au atom. The Xe–Au bond length is 2.69 Å. Au is bonded in a distorted T-shaped geometry to one Xe and three F atoms. There are a spread of Au–F bond distances ranging from 2.09–2.25 Å. There are two inequivalent Sb sites. In the first Sb site, Sb is bonded in an octahedral geometry to six F atoms. There are a spread of Sb–F bond distances ranging from 1.90–2.02 Å. In the second Sb site, Sb is bonded in an octahedral geometry to six F atoms. There are a spread of Sb–F bond distances ranging from 1.90–1.99 Å. There are nine inequivalent F sites. In the first F site, F is bonded in a linear geometry to two equivalent Au atoms. In the second F site, F is bonded in a bent 150 degrees geometry to one Au and one Sb atom. In the third F site, F is bonded in a single-bond geometry to one Sb atom. In the fourth F site, F is bonded in a single-bond geometry to one Sb atom. In the fifth F site, F is bonded in a single-bond geometry to one Sb atom. In the sixth F site, F is bonded in a single-bond geometry to one Sb atom. In the seventh F site, F is bonded in a single-bond geometry to one Sb atom. In the eighth F site, F is bonded in a distorted bent 150 degrees geometry to one Au and one Sb atom. In the ninth F site, F is bonded in a single-bond geometry to one Sb atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaV5H18N2O19 by Materials Project

Na(H2O)5V5O14(NH4)2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four ammonium molecules, one Na(H2O)5 cluster, and one V5O14 cluster. In the Na(H2O)5 cluster, Na1+ is bonded to six O2- atoms to form edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.37–2.49 Å. There are ten inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Na1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the V5O14 cluster, there are five inequivalent V5+ sites. In the first V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.62–2.44 Å. In the second V5+ site, V5+ is bonded to six O2- atoms to form distorted edge-sharing VO6 octahedra. There are a spread of V–O bond distances ranging from 1.73–2.09 Å. In the third V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.66–2.27 Å. In the fourth V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.65–2.30 Å. In the fifth V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.64–2.36 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to two V5+ atoms. In the second O2- site, O2- is bonded in a trigonal non-coplanar geometry to three V5+ atoms. In the third O2- site, O2- is bonded in a trigonal non-coplanar geometry to three V5+ atoms. In the fourth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the sixth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the eighth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two V5+ atoms. In the tenth O2- site, O2- is bonded to six V5+ atoms to form distorted edge-sharing OV6 octahedra. In the eleventh O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the twelfth O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the thirteenth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the fourteenth O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiV5H18N2O19 by Materials Project

Li(H2O)5V5O14(NH4)2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four ammonium molecules, one Li(H2O)5 cluster, and one V5O14 cluster. In the Li(H2O)5 cluster, Li1+ is bonded to six O2- atoms to form edge-sharing LiO6 octahedra. There are a spread of Li–O bond distances ranging from 2.10–2.28 Å. There are ten inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Li1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to one Li1+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Li1+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Li1+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Li1+ and two H1+ atoms. In the V5O14 cluster, there are five inequivalent V5+ sites. In the first V5+ site, V5+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.63–2.44 Å. In the second V5+ site, V5+ is bonded to six O2- atoms to form distorted edge-sharing VO6 octahedra. There are a spread of V–O bond distances ranging from 1.73–2.11 Å. In the third V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.66–2.26 Å. In the fourth V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.65–2.31 Å. In the fifth V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.63–2.37 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the third O2- site, O2- is bonded in a water-like geometry to two V5+ atoms. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the sixth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three V5+ atoms. In the seventh O2- site, O2- is bonded in a trigonal non-coplanar geometry to three V5+ atoms. In the eighth O2- site, O2- is bonded to six V5+ atoms to form distorted edge-sharing OV6 octahedra. In the ninth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the tenth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the eleventh O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the twelfth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the thirteenth O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the fourteenth O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BiS by Materials Project

BiS crystallizes in the orthorhombic Fmm2 space group. The structure is one-dimensional and consists of four BiS ribbons oriented in the (1, 0, 0) direction. there are three inequivalent Bi2+ sites. In the first Bi2+ site, Bi2+ is bonded in a distorted single-bond geometry to one S2- atom. The Bi–S bond length is 2.82 Å. In the second Bi2+ site, Bi2+ is bonded to five S2- atoms to form a mixture of corner and edge-sharing BiS5 square pyramids. There are a spread of Bi–S bond distances ranging from 2.77–2.93 Å. In the third Bi2+ site, Bi2+ is bonded in a 5-coordinate geometry to five S2- atoms. There are a spread of Bi–S bond distances ranging from 2.73–3.04 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 1-coordinate geometry to two Bi2+ atoms. In the second S2- site, S2- is bonded in a 1-coordinate geometry to four Bi2+ atoms. In the third S2- site, S2- is bonded in a distorted single-bond geometry to five Bi2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SNF3 by Materials Project

NSF3 is Cubane-derived structured and crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of four amino-sulfur trifluoride molecules. N5+ is bonded in a single-bond geometry to one S2- atom. The N–S bond length is 1.43 Å. S2- is bonded in a distorted trigonal pyramidal geometry to one N5+ and three F1- atoms. All S–F bond lengths are 1.59 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one S2- atom. In the second F1- site, F1- is bonded in a single-bond geometry to one S2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AgSb(SeF3)2 by Materials Project

AgSbF6(Se)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional and consists of twenty-four selen molecules and one AgSbF6 framework. In the AgSbF6 framework, there are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a distorted single-bond geometry to one F1- atom. The Ag–F bond length is 3.23 Å. In the second Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Ag–F bond distances ranging from 2.45–2.70 Å. There are three inequivalent Sb3+ sites. In the first Sb3+ site, Sb3+ is bonded in an octahedral geometry to six F1- atoms. There is two shorter (1.92 Å) and four longer (1.93 Å) Sb–F bond length. In the second Sb3+ site, Sb3+ is bonded in an octahedral geometry to six F1- atoms. There is two shorter (1.92 Å) and four longer (1.93 Å) Sb–F bond length. In the third Sb3+ site, Sb3+ is bonded in an octahedral geometry to six F1- atoms. There is two shorter (1.92 Å) and four longer (1.93 Å) Sb–F bond length. There are ten inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Ag1+ and one Sb3+ atom. In the third F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Ag1+ and one Sb3+ atom. In the fourth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Ag1+ and one Sb3+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the sixth F1- site, F1- is bonded in a distorted linear geometry to one Ag1+ and one Sb3+ atom. In the seventh F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Ag1+ and one Sb3+ atom. In the eighth F1- site, F1- is bonded in a distorted bent 120 degrees geometry to one Ag1+ and one Sb3+ atom. In the ninth F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the tenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Ag1+ and one Sb3+ atom.

36 MATERIALS SCIENCE↗
NASA NTRSDate not supplied

REACTER 2.0: Quantum-Informed Reaction Constraints and Automated Interaction Typing

REACTER is a heuristic method for modeling chemical reactions in classical molecular dynamics simulations, implemented in LAMMPS as fix bond/react. The authors recently extended LAMMPS to support alphanumeric labels for atom types, bond types etc., which enables the pre- and post-reaction templates required by the REACTER protocol to be portable between different simulations and greatly simplifies the task of creating simulation-ready reaction templates. To further increase the generality of reaction templates, support for wildcard characters within atom types has been added, along with the automatic assignment of interaction types for new bonds, angles, etc. based on the involved atom types. In some cases, this feature can express a class of reactions with one pair of reaction templates, where previously dozens may have been required. Advanced reaction constraints have also been added, including an Arrhenius constraint to enforce an effective activation energy, a root-mean-square-deviation option for complex geometrical constraints, as well as a custom constraint that leverages LAMMPS’ powerful built-in variable framework. Other new features include variable support for various inputs (e.g., to allow reaction rates or cutoffs to be dependent on overall conversion), on-the-fly update of molecule IDs, and the ability to create new atoms positioned with respect to the reaction site. The new features are applied to modeling polymeric, thermosetting and composite materials, and advanced applications of the new reaction constraints are demonstrated. For example, REACTER is shown to accurately reproduce mechanically-induced bond breaking, as characterized by third-order DFT-based tight-binding (DFTB3) simulations, via a constraint on the total potential energy of the involved atoms.

polymer simulations↗