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DOE OSTI2020

Materials Data on ReBi3O8 by Materials Project

Bi3ReO8 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. there are two inequivalent Re7+ sites. In the first Re7+ site, Re7+ is bonded in a tetrahedral geometry to four O2- atoms. All Re–O bond lengths are 1.76 Å. In the second Re7+ site, Re7+ is bonded in a tetrahedral geometry to four O2- atoms. There is three shorter (1.75 Å) and one longer (1.77 Å) Re–O bond length. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.20–3.06 Å. In the second Bi3+ site, Bi3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.18–2.92 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to four Bi3+ atoms. 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+ and three equivalent Bi3+ atoms. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to one Re7+ and one Bi3+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to four Bi3+ atoms. In the sixth O2- site, O2- is bonded in a single-bond geometry to one Re7+ and one Bi3+ atom. In the seventh O2- site, O2- is bonded in a trigonal non-coplanar geometry to three equivalent Bi3+ atoms. In the eighth O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CuSn3H27C9NCl by Materials Project

CuSn3C9NH27Cl crystallizes in the cubic P2_13 space group. The structure is zero-dimensional and consists of eight CuSn3C9NH27Cl clusters. In four of the CuSn3C9NH27Cl clusters, Cu1+ is bonded in a linear geometry to one N3- and one Cl1- atom. The Cu–N bond length is 1.88 Å. The Cu–Cl bond length is 2.11 Å. Sn4+ is bonded to three C4- and one N3- atom to form corner-sharing SnC3N tetrahedra. There are one shorter (2.16 Å) and two longer (2.17 Å) Sn–C bond lengths. The Sn–N bond length is 2.17 Å. There are three inequivalent C4- sites. In the first C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Sn4+ and three H1+ atoms. All C–H bond lengths are 1.10 Å. In the second C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Sn4+ and three H1+ atoms. All C–H bond lengths are 1.10 Å. In the third C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Sn4+ and three H1+ atoms. All C–H bond lengths are 1.10 Å. N3- is bonded in a tetrahedral geometry to one Cu1+ and three equivalent Sn4+ atoms. There are nine inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. Cl1- is bonded in a single-bond geometry to one Cu1+ atom. In four of the CuSn3C9NH27Cl clusters, Cu1+ is bonded in a linear geometry to one N3- and one Cl1- atom. The Cu–N bond length is 1.88 Å. The Cu–Cl bond length is 2.11 Å. Sn4+ is bonded to three C4- and one N3- atom to form corner-sharing SnC3N tetrahedra. There are one shorter (2.16 Å) and two longer (2.17 Å) Sn–C bond lengths. The Sn–N bond length is 2.18 Å. There are three inequivalent C4- sites. In the first C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Sn4+ and three H1+ atoms. All C–H bond lengths are 1.10 Å. In the second C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Sn4+ and three H1+ atoms. There is one shorter (1.09 Å) and two longer (1.10 Å) C–H bond length. In the third C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Sn4+ and three H1+ atoms. All C–H bond lengths are 1.10 Å. N3- is bonded in a tetrahedral geometry to one Cu1+ and three equivalent Sn4+ atoms. There are nine inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. Cl1- is bonded in a single-bond geometry to one Cu1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag5Te2Cl by Materials Project

Ag5Te2Cl crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are twenty inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 1-coordinate geometry to one Ag1+, two Te2-, and one Cl1- atom. The Ag–Ag bond length is 2.94 Å. Both Ag–Te bond lengths are 2.79 Å. The Ag–Cl bond length is 2.76 Å. In the second Ag1+ site, Ag1+ is bonded in a 1-coordinate geometry to one Ag1+, three Te2-, and one Cl1- atom. The Ag–Ag bond length is 3.06 Å. There are a spread of Ag–Te bond distances ranging from 2.80–2.97 Å. The Ag–Cl bond length is 2.89 Å. In the third Ag1+ site, Ag1+ is bonded in a 2-coordinate geometry to one Ag1+, two Te2-, and two Cl1- atoms. The Ag–Ag bond length is 2.86 Å. There are one shorter (2.83 Å) and one longer (2.89 Å) Ag–Te bond lengths. There are one shorter (2.66 Å) and one longer (2.73 Å) Ag–Cl bond lengths. In the fourth Ag1+ site, Ag1+ is bonded in a 1-coordinate geometry to one Ag1+, three Te2-, and one Cl1- atom. The Ag–Ag bond length is 2.98 Å. There are a spread of Ag–Te bond distances ranging from 2.88–3.17 Å. The Ag–Cl bond length is 2.79 Å. In the fifth Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four Ag1+ and four Te2- atoms. There are a spread of Ag–Ag bond distances ranging from 3.02–3.10 Å. There are a spread of Ag–Te bond distances ranging from 2.88–3.07 Å. In the sixth Ag1+ site, Ag1+ is bonded in a 2-coordinate geometry to two Ag1+, two Te2-, and two Cl1- atoms. There are one shorter (2.95 Å) and one longer (3.06 Å) Ag–Ag bond lengths. There are one shorter (2.87 Å) and one longer (2.92 Å) Ag–Te bond lengths. There are one shorter (2.68 Å) and one longer (2.97 Å) Ag–Cl bond lengths. In the seventh Ag1+ site, Ag1+ is bonded in a 10-coordinate geometry to seven Ag1+ and three Te2- atoms. There are a spread of Ag–Ag bond distances ranging from 2.98–3.02 Å. There are a spread of Ag–Te bond distances ranging from 2.92–3.06 Å. In the eighth Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to one Ag1+, three Te2-, and one Cl1- atom. The Ag–Ag bond length is 2.96 Å. There are a spread of Ag–Te bond distances ranging from 2.80–2.90 Å. The Ag–Cl bond length is 3.17 Å. In the ninth Ag1+ site, Ag1+ is bonded in a 1-coordinate geometry to two Ag1+, three Te2-, and one Cl1- atom. The Ag–Ag bond length is 3.09 Å. There are a spread of Ag–Te bond distances ranging from 2.81–3.41 Å. The Ag–Cl bond length is 2.80 Å. In the tenth Ag1+ site, Ag1+ is bonded in a 1-coordinate geometry to three Ag1+ and four Te2- atoms. The Ag–Ag bond length is 3.01 Å. There are a spread of Ag–Te bond distances ranging from 2.86–3.13 Å. In the eleventh Ag1+ site, Ag1+ is bonded in a 1-coordinate geometry to one Ag1+, three Te2-, and one Cl1- atom. The Ag–Ag bond length is 3.02 Å. There are a spread of Ag–Te bond distances ranging from 2.86–3.02 Å. The Ag–Cl bond length is 2.88 Å. In the twelfth Ag1+ site, Ag1+ is bonded in a 8-coordinate geometry to four Ag1+, three Te2-, and one Cl1- atom. There are one shorter (2.91 Å) and one longer (2.96 Å) Ag–Ag bond lengths. There are a spread of Ag–Te bond distances ranging from 2.88–3.00 Å. The Ag–Cl bond length is 3.23 Å. In the thirteenth Ag1+ site, Ag1+ is bonded in a 1-coordinate geometry to three Ag1+, three Te2-, and one Cl1- atom. There are one shorter (2.96 Å) and one longer (3.02 Å) Ag–Ag bond lengths. There are a spread of Ag–Te bond distances ranging from 2.83–3.58 Å. The Ag–Cl bond length is 2.74 Å. In the fourteenth Ag1+ site, Ag1+ is bonded in a 2-coordinate geometry to one Ag1+, two Te2-, and two Cl1- atoms. There are one shorter (2.85 Å) and one longer (2.88 Å) Ag–Te bond lengths. There are one shorter (2.85 Å) and one longer (2.86 Å) Ag–Cl bond lengths. In the fifteenth Ag1+ site, Ag1+ is bonded in a 1-coordinate geometry to two Ag1+, three Te2-, and one Cl1- atom. There are a spread of Ag–Te bond distances ranging from 2.80–3.45 Å. The Ag–Cl bond length is 2.91 Å. In the sixteenth Ag1+ site, Ag1+ is bonded in a 1-coordinate geometry to two Ag1+, two Te2-, and one Cl1- atom. There are one shorter (2.81 Å) and one longer (2.86 Å) Ag–Te bond lengths. The Ag–Cl bond length is 2.79 Å. In the seventeenth Ag1+ site, Ag1+ is bonded in a 1-coordinate geometry to three Ag1+, four Te2-, and one Cl1- atom. There are a spread of Ag–Te bond distances ranging from 2.79–3.55 Å. The Ag–Cl bond length is 3.00 Å. In the eighteenth Ag1+ site, Ag1+ is bonded in a 1-coordinate geometry to two Ag1+, four Te2-, and one Cl1- atom. The Ag–Ag bond length is 2.94 Å. There are a spread of Ag–Te bond distances ranging from 2.84–3.62 Å. The Ag–Cl bond length is 2.81 Å. In the nineteenth Ag1+ site, Ag1+ is bonded in a 9-coordinate geometry to five Ag1+, three Te2-, and one Cl1- atom. The Ag–Ag bond length is 2.99 Å. There are a spread of Ag–Te bond distances ranging from 2.88–3.09 Å. The Ag–Cl bond length is 3.04 Å. In the twentieth Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to one Ag1+, two Te2-, and two Cl1- atoms. There are one shorter (2.83 Å) and one longer (2.84 Å) Ag–Te bond lengths. There are one shorter (2.74 Å) and one longer (3.13 Å) Ag–Cl bond lengths. There are eight inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 8-coordinate geometry to eight Ag1+ atoms. In the second Te2- site, Te2- is bonded in a 6-coordinate geometry to eight Ag1+ atoms. In the third Te2- site, Te2- is bonded in a 8-coordinate geometry to eight Ag1+ atoms. In the fourth Te2- site, Te2- is bonded in a 6-coordinate geometry to six Ag1+ atoms. In the fifth Te2- site, Te2- is bonded in a 8-coordinate geometry to eight Ag1+ atoms. In the sixth Te2- site, Te2- is bonded in a 7-coordinate geometry to seven Ag1+ atoms. In the seventh Te2- site, Te2- is bonded in a 7-coordinate geometry to seven Ag1+ atoms. In the eighth Te2- site, Te2- is bonded in a 6-coordinate geometry to six Ag1+ atoms. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 6-coordinate geometry to six Ag1+ atoms. In the second Cl1- site, Cl1- is bonded in a 5-coordinate geometry to five Ag1+ atoms. In the third Cl1- site, Cl1- is bonded in a 5-coordinate geometry to five Ag1+ atoms. In the fourth Cl1- site, Cl1- is bonded in a 5-coordinate geometry to five Ag1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti2O by Materials Project

Ti2O crystallizes in the monoclinic P2/m space group. The structure is two-dimensional and consists of one Ti2O sheet oriented in the (0, 0, 1) direction. there are three inequivalent Ti sites. In the first Ti site, Ti is bonded in a 4-coordinate geometry to four O atoms. All Ti–O bond lengths are 2.06 Å. In the second Ti site, Ti is bonded in an L-shaped geometry to two equivalent O atoms. Both Ti–O bond lengths are 2.04 Å. In the third Ti site, Ti is bonded in a 3-coordinate geometry to three O atoms. There are a spread of Ti–O bond distances ranging from 2.13–2.54 Å. There are two inequivalent O sites. In the first O site, O is bonded to six Ti atoms to form a mixture of distorted corner, edge, and face-sharing OTi6 octahedra. The corner-sharing octahedra tilt angles range from 6–58°. In the second O site, O is bonded to six Ti atoms to form a mixture of corner, edge, and face-sharing OTi6 octahedra. The corner-sharing octahedra tilt angles range from 37–58°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ta6Br12ClO15 by Materials Project

(TaO)6(O2)3ClO3(Br)12 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of twenty-four hydrobromic acid molecules, six hydrogen peroxide molecules, twelve oxotantalum molecules, and two ClO3 clusters. In each ClO3 cluster, there are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one O2- and one Cl1- atom. The O–O bond length is 1.31 Å. The O–Cl bond length is 2.47 Å. In the second O2- site, O2- is bonded in a single-bond geometry to one O2- atom. The O–O bond length is 1.33 Å. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two O2- atoms. Cl1- is bonded in a distorted single-bond geometry to one O2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mo2NCl7 by Materials Project

Mo2NCl7 crystallizes in the triclinic P-1 space group. The structure is one-dimensional and consists of two Mo2NCl7 ribbons oriented in the (1, 1, 0) direction. there are four inequivalent Mo5+ sites. In the first Mo5+ site, Mo5+ is bonded in a 6-coordinate geometry to one N3- and five Cl1- atoms. The Mo–N bond length is 1.72 Å. There are a spread of Mo–Cl bond distances ranging from 2.27–2.85 Å. In the second Mo5+ site, Mo5+ is bonded in a 6-coordinate geometry to one N3- and five Cl1- atoms. The Mo–N bond length is 1.72 Å. There are a spread of Mo–Cl bond distances ranging from 2.26–2.83 Å. In the third Mo5+ site, Mo5+ is bonded to one N3- and five Cl1- atoms to form distorted face-sharing MoNCl5 octahedra. The Mo–N bond length is 1.99 Å. There are a spread of Mo–Cl bond distances ranging from 2.27–2.50 Å. In the fourth Mo5+ site, Mo5+ is bonded to one N3- and five Cl1- atoms to form distorted face-sharing MoNCl5 octahedra. The Mo–N bond length is 2.00 Å. There are a spread of Mo–Cl bond distances ranging from 2.27–2.51 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a linear geometry to two Mo5+ atoms. In the second N3- site, N3- is bonded in a linear geometry to two Mo5+ atoms. There are fourteen inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two Mo5+ atoms. In the second Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two Mo5+ atoms. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Mo5+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Mo5+ atom. In the fifth Cl1- site, Cl1- is bonded in a single-bond geometry to one Mo5+ atom. In the sixth Cl1- site, Cl1- is bonded in a single-bond geometry to one Mo5+ atom. In the seventh Cl1- site, Cl1- is bonded in a distorted L-shaped geometry to two Mo5+ atoms. In the eighth Cl1- site, Cl1- is bonded in an L-shaped geometry to two Mo5+ atoms. In the ninth Cl1- site, Cl1- is bonded in a distorted L-shaped geometry to two Mo5+ atoms. In the tenth Cl1- site, Cl1- is bonded in a single-bond geometry to one Mo5+ atom. In the eleventh Cl1- site, Cl1- is bonded in a single-bond geometry to one Mo5+ atom. In the twelfth Cl1- site, Cl1- is bonded in a single-bond geometry to one Mo5+ atom. In the thirteenth Cl1- site, Cl1- is bonded in a single-bond geometry to one Mo5+ atom. In the fourteenth Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two Mo5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on H2WO5 by Materials Project

WH2O5 crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of two WH2O5 ribbons oriented in the (0, 1, 0) direction. W is bonded to seven O atoms to form a mixture of distorted edge and corner-sharing WO7 pentagonal bipyramids. There are a spread of W–O bond distances ranging from 1.75–2.29 Å. There are two inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. In the second H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. There are five inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one W atom. In the second O site, O is bonded in a distorted trigonal non-coplanar geometry to three equivalent W atoms. In the third O site, O is bonded in a water-like geometry to one W and two H atoms. In the fourth O site, O is bonded in a 1-coordinate geometry to one W and one O atom. The O–O bond length is 1.47 Å. In the fifth O site, O is bonded in a 1-coordinate geometry to one W and one O atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on S(IN)2 by Materials Project

S(NI)2 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one S(NI)2 sheet oriented in the (1, 1, 0) direction. there are four inequivalent N2+ sites. In the first N2+ site, N2+ is bonded in a 3-coordinate geometry to one S2- and two I1- atoms. The N–S bond length is 1.57 Å. There are one shorter (2.12 Å) and one longer (2.73 Å) N–I bond lengths. In the second N2+ site, N2+ is bonded in a 3-coordinate geometry to one S2- and two I1- atoms. The N–S bond length is 1.56 Å. There are one shorter (2.12 Å) and one longer (2.67 Å) N–I bond lengths. In the third N2+ site, N2+ is bonded in a distorted trigonal planar geometry to one S2- and two I1- atoms. The N–S bond length is 1.55 Å. There are one shorter (2.08 Å) and one longer (2.74 Å) N–I bond lengths. In the fourth N2+ site, N2+ is bonded in a distorted trigonal planar geometry to one S2- and two I1- atoms. The N–S bond length is 1.55 Å. There are one shorter (2.08 Å) and one longer (2.74 Å) N–I bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a bent 120 degrees geometry to two N2+ atoms. In the second S2- site, S2- is bonded in a bent 120 degrees geometry to two N2+ atoms. There are four inequivalent I1- sites. In the first I1- site, I1- is bonded in a linear geometry to two N2+ atoms. In the second I1- site, I1- is bonded in a distorted linear geometry to two N2+ atoms. In the third I1- site, I1- is bonded in a distorted linear geometry to two N2+ atoms. In the fourth I1- site, I1- is bonded in a distorted linear geometry to two N2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Density Functional Theory Study of the Adsorption and Dissociation of Copper(I) Acetamidinates on Ni(110): The Effect of the Substrate

In order to assess the role of a metal substrates on the thermal chemistry of adsorbed acetamidinate metalorganic compounds, we have studied the surface chemistry of copper(I)–N,N'-dimethylacetamidinate on Ni(110) using density functional theory and contrasted it with similar calculations we previously carried out on Cu(110). At low coverages, it was found that, in its most stable configuration, the molecular adsorption of copper(I)–N,N'-dimethylacetamidinate dimers occurs with the Cu atoms occupying surface hollow sites. In this work, the ligands reorient away from those metal centers, and the N atoms develop new direct bonds with surface Ni atoms. However, this configuration is not stable and decomposes by losing both ligands to the surface. In the final state, the two ligands bind via their N atoms to Ni sites one lattice space away from the sites where the Cu atoms remain, with their molecular planes perpendicular to that of the surface. This is in contrast with what happens in the case of adsorption on Cu(110), where the Cu atoms from the metalorganic complex still occupy hollow sites but where only one of the ligands breaks away and binds directly to the surface; the other remains on top of the two Cu ions. In terms of the energetics of adsorption and decomposition, the reactions on Ni(110) are much more exothermic than on Cu(110). Further analysis of the distribution of charge within the adsorbates shows a minor reduction of the Cu atoms of the dimer upon interaction with the surface; full reduction to metallic copper is complete only when both ligands have fully migrated to their new Ni surface sites.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Ultrafast Optomechanical Strain in Layered GeS

Strong coupling between light and mechanical strain forms the foundation for next-generation optical micro- and nano-electromechanical systems. Such optomechanical responses in two-dimensional materials present novel types of functionalities arising from the weak van der Waals bond between atomic layers. In this paper, by using structure-sensitive megaelectronvolt ultrafast electron diffraction, we report the experimental observation of optically driven ultrafast in-plane strain in the layered group IV monochalcogenide germanium sulfide (GeS). Surprisingly, the photoinduced structural deformation exhibits strain amplitudes of order 0.1% with a 10 ps fast response time and a significant in-plane anisotropy between zigzag and armchair crystallographic directions. Rather than arising due to heating, experimental and theoretical investigations suggest deformation potentials caused by electronic density redistribution and converse piezoelectric effects generated by photoinduced electric fields are the dominant contributors to the observed dynamic anisotropic strains. Our observations define new avenues for ultrafast optomechanical control and strain engineering within functional devices.

2D materials↗
DOE OSTI2022

Hydrogen separation with a graphenylene monolayer: Diffusion Monte Carlo study

Here, we performed fixed-node diffusion Monte Carlo (DMC) calculations to investigate structural and energetic properties of graphenylene (GPNL), a two-dimensional network of sp 2 -bonded carbon atoms with large near-circular pores, and its H 2 separation performance for gas mixtures. We have found that the energetic stability of a GPNL monolayer is comparable to that of γ-graphyne, as evidenced by its large cohesive energy of 6.755(3) eV/atom. Diffusion barriers of several gas molecules, including hydrogen, through a GPNL membrane were determined from the analysis of their adsorption energies depending on the adsorption distance, which led to our estimation for hydrogen selectivity with respect to other target molecules. DMC hydrogen selectivity of a GPNL monolayer was found to be exceptionally high at 300 K, as high as 10 10 –10 11 against CO and N 2 gases. This, along with high hydrogen permeance due to its generic pore structure, leads us to conclude that GPNL is a promising membrane to be used as a high-performance hydrogen separator from gas mixtures. We find that when compared to our DMC results, DFT calculations tend to overestimate H 2 selectivity, which is mostly due to their inaccurate description of short-range repulsive interactions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Large Angle Rocking Beam Electron Diffraction Utilizing Electron Direct Detector

Electron diffraction of a crystal is fundamentally a function of the potential of that crystal. The intensity of electron diffraction patterns is, as a result, sensitive to the charge density of atoms and bonding inside crystals. Experimentally, the traditional method to probe this information is quantitative Convergent Beam Electron Diffraction (CBED). Quantitative CBED or QCEBD is a method which uses dynamic diffraction theory to quantify CBED intensities and to extract information about crystal structure and bonding. The sensitivity of dynamical scattering is leveraged to measure crystal symmetry and crystal structure factors. At its limit, electron structure factors are measured at high accuracy allowing access to chemical bonding information, which corroborate theoretical calculations through multipole model refinements of the experimental charge density. The primary limit to QCBED is the requirement of a non-overlapping convergent beam. This subsequently limits QCBED to crystals with small unit cells which are stable under the focused probe.

Busch, Robert↗
DOE OSTI2021

Artificial intelligence “sees” split electrons

Chemical bonds between atoms are stabilized by the exchange-correlation (xc) energy, a quantum-mechanical effect in which “social distancing” by electrons lowers their electrostatic repulsion energy. Kohn-Sham density functional theory (DFT) states that the electron density determines this xc energy, but the density functional must be approximated. Furthermore, this is usually done by satisfying exact constraints of the exact functional (making the approximation predictive), by fitting to data (making it interpolative), or both. Two exact constraints—the ensemble-based piecewise linear variation of the total energy with respect to fractional electron number and fractional electron z-component of spin —require hard-to-control nonlocality. On page 1385 of this issue, Kirkpatrick et al. have taken a big step toward more accurate predictions for chemistry through the machine learning of molecular data plus the fractional charge and spin constraints, expressed as data that a machine can learn.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2020

rlmolecule: A library for general-purpose material and molecular optimization using AlphaZero-style reinforcement learning

This library includes in-progress code for the optimization of materials and molecules using reinforcement learning. This project seeks to develop a generalized machine learning approach for optimizing targeted, and often complex, functional properties over the space of possible material structures, allowing faster identification of promising candidates. Electronic and transport properties of materials are determined by their molecular structure (for molecules) or their crystal structure (for in-organic crystalline materials). The atomic composition, bonding, and 3-D-spatial arrangement in these systems therefore represent a vast, discontinuous search space for optimal candidates. This library implements AlphaZero style reinforcement learning applied to two worked examples: the optimization of stable organic radicals for redox flow batteries, and the determination of stable electrolyte species for solid state batteries. The current code contains proof-of-concept results run on the Eagle HPC system, while the completed package will be a flexible tool for material optimization across of number of energy-relevant fields, which leverages cloud compute resources for the majority of the computational heavy lifting.

Biagioni, David↗
DOE OSTI2020

Nucleation, growth, and superlattice formation of nanocrystals observed in liquid cell transmission electron microscopy

This work reviews the advancements and prospects of liquid cell transmission electron microscopy (TEM) imaging and analysis methods in understanding the nucleation, growth, etching, and assembly dynamics of nanocrystals. The bonding of atoms into nanoscale crystallites produces materials with nonadditive properties unique to their size and geometry. The recent application of in situ liquid cell TEM to nanocrystal development has initiated a paradigm shift, (1) from trial-and-error synthesis to a mechanistic understanding of the “synthetic reactions” responsible for the emergence of crystallites from a disordered soup of reactive species (e.g., ions, atoms, molecules) and shape-defined growth or etching; and (2) from post-processing characterization of the nanocrystals’ superlattice assemblies to in situ imaging and mapping of the fundamental interactions and energy landscape governing their collective phase behaviors. Imaging nanocrystal formation and assembly processes on the single-particle level in solution immediately impacts many existing fields, including materials science, nanochemistry, colloidal science, biology, environmental science, electrochemistry, mineralization, soft condensed-matter physics, and device fabrication.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CO by Materials Project

CO is alpha carbon monoxide structured and crystallizes in the cubic P2_13 space group. The structure is zero-dimensional and consists of four formaldehyde molecules. C2+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.14 Å. O2- is bonded in a single-bond geometry to one C2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HgCl by Materials Project

HgCl is BCT5 structured and crystallizes in the tetragonal I4/mmm space group. The structure is zero-dimensional and consists of four mercury chloride molecules. Hg1+ is bonded in a distorted single-bond geometry to one Cl1- atom. The Hg–Cl bond length is 2.44 Å. Cl1- is bonded in a distorted single-bond geometry to one Hg1+ atom.

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