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At least 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on AlC3(NCl2)3 by Materials Project

AlC3(NCl2)3 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four AlC3(NCl2)3 clusters. In two of the AlC3(NCl2)3 clusters, Al3+ is bonded in a tetrahedral geometry to one N3- and three Cl1- atoms. The Al–N bond length is 2.06 Å. There are one shorter (2.13 Å) and two longer (2.14 Å) Al–Cl bond lengths. There are three inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a trigonal planar geometry to two N3- and one Cl1- atom. There is one shorter (1.32 Å) and one longer (1.37 Å) C–N bond length. The C–Cl bond length is 1.69 Å. In the second C4+ site, C4+ is bonded in a trigonal planar geometry to two N3- and one Cl1- atom. There is one shorter (1.32 Å) and one longer (1.37 Å) C–N bond length. The C–Cl bond length is 1.69 Å. In the third C4+ site, C4+ is bonded in a trigonal planar geometry to two N3- and one Cl1- atom. Both C–N bond lengths are 1.34 Å. The C–Cl bond length is 1.69 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a bent 120 degrees geometry to two C4+ atoms. In the second N3- site, N3- is bonded in a trigonal planar geometry to one Al3+ and two C4+ atoms. In the third N3- site, N3- is bonded in a bent 120 degrees geometry to two C4+ atoms. There are six inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one C4+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one C4+ atom. In the fifth Cl1- site, Cl1- is bonded in a single-bond geometry to one C4+ atom. In the sixth Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom. In two of the AlC3(NCl2)3 clusters, Al3+ is bonded in a tetrahedral geometry to one N3- and three Cl1- atoms. The Al–N bond length is 2.09 Å. There are two shorter (2.13 Å) and one longer (2.15 Å) Al–Cl bond lengths. There are three inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a trigonal planar geometry to two N3- and one Cl1- atom. Both C–N bond lengths are 1.34 Å. The C–Cl bond length is 1.69 Å. In the second C4+ site, C4+ is bonded in a trigonal planar geometry to two N3- and one Cl1- atom. There is one shorter (1.32 Å) and one longer (1.37 Å) C–N bond length. The C–Cl bond length is 1.69 Å. In the third C4+ site, C4+ is bonded in a trigonal planar geometry to two N3- and one Cl1- atom. There is one shorter (1.32 Å) and one longer (1.37 Å) C–N bond length. The C–Cl bond length is 1.69 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal planar geometry to one Al3+ and two C4+ atoms. In the second N3- site, N3- is bonded in a bent 120 degrees geometry to two C4+ atoms. In the third N3- site, N3- is bonded in a bent 120 degrees geometry to two C4+ atoms. There are six inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one C4+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom. In the fifth Cl1- site, Cl1- is bonded in a single-bond geometry to one C4+ atom. In the sixth Cl1- site, Cl1- is bonded in a single-bond geometry to one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CuH22C8N10O by Materials Project

CuH20(C4N5)2H2O crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of eight water molecules and eight CuH20(C4N5)2 clusters. In four of the CuH20(C4N5)2 clusters, Cu2+ is bonded in a square co-planar geometry to four N3- atoms. There is two shorter (1.94 Å) and two longer (1.99 Å) Cu–N bond length. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.46 Å. All C–H bond lengths are 1.10 Å. In the second C1+ site, C1+ is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.45 Å. There are a spread of C–H bond distances ranging from 1.09–1.11 Å. In the third C1+ site, C1+ is bonded in a trigonal planar geometry to three N3- atoms. There are a spread of C–N bond distances ranging from 1.33–1.39 Å. In the fourth C1+ site, C1+ is bonded in a trigonal planar geometry to three N3- atoms. There is one shorter (1.33 Å) and two longer (1.37 Å) C–N bond length. There are five inequivalent N3- sites. In the first N3- site, N3- is bonded in a bent 120 degrees geometry to two C1+ atoms. In the second N3- site, N3- is bonded in a distorted trigonal planar geometry to one Cu2+, one C1+, and one H1+ atom. The N–H bond length is 1.02 Å. In the third N3- site, N3- is bonded in a distorted trigonal planar geometry to one Cu2+, one C1+, and one H1+ atom. The N–H bond length is 1.03 Å. In the fourth N3- site, N3- is bonded in a trigonal planar geometry to three C1+ atoms. In the fifth N3- site, N3- is bonded in a trigonal non-coplanar geometry to one C1+ and two H1+ atoms. There is one shorter (1.01 Å) and one longer (1.02 Å) N–H bond length. There are ten inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C1+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C1+ atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C1+ atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C1+ atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one C1+ atom. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one C1+ atom. In four of the CuH20(C4N5)2 clusters, Cu2+ is bonded in a square co-planar geometry to four N3- atoms. All Cu–N bond lengths are 1.96 Å. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a trigonal planar geometry to three N3- atoms. There are a spread of C–N bond distances ranging from 1.33–1.38 Å. In the second C1+ site, C1+ is bonded in a trigonal planar geometry to three N3- atoms. There are a spread of C–N bond distances ranging from 1.33–1.38 Å. In the third C1+ site, C1+ is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.45 Å. There is one shorter (1.09 Å) and two longer (1.10 Å) C–H bond length. In the fourth C1+ site, C1+ is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.45 Å. All C–H bond lengths are 1.10 Å. There are five inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted trigonal planar geometry to one Cu2+, one C1+, and one H1+ atom. The N–H bond length is 1.02 Å. In the second N3- site, N3- is bonded in a distorted trigonal planar geometry to one Cu2+, one C1+, and one H1+ atom. The N–H bond length is 1.02 Å. In the third N3- site, N3- is bonded in a distorted trigonal planar geometry to one C1+ and two H1+ atoms. Both N–H bond lengths are 1.02 Å. In the fourth N3- site, N3- is bonded in a bent 120 degrees geometry to two C1+ atoms. In the fifth N3- site, N3- is bonded in a trigonal planar geometry to three C1+ atoms. There are ten 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 C1+ atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C1+ atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C1+ atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C1+ atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C1+ atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one C1+ atom. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Co3SnC12ClO12 by Materials Project

(Co(CO)4)3SnCl crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four tin chloride (sncl) molecules and twelve Co(CO)4 clusters. In four of the Co(CO)4 clusters, Co+1.67+ is bonded in a trigonal pyramidal geometry to four C+1.33+ atoms. There is two shorter (1.77 Å) and two longer (1.78 Å) Co–C bond length. There are four inequivalent C+1.33+ sites. In the first C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.33+ site, C+1.33+ is bonded in a distorted single-bond geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.15 Å. In the fourth C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In eight of the Co(CO)4 clusters, Co+1.67+ is bonded in a trigonal pyramidal geometry to four C+1.33+ atoms. There is two shorter (1.77 Å) and two longer (1.78 Å) Co–C bond length. There are four inequivalent C+1.33+ sites. In the first C+1.33+ site, C+1.33+ is bonded in a distorted single-bond geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.15 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HgC4NCl3 by Materials Project

HgCl2C4NCl crystallizes in the monoclinic P2_1 space group. The structure is one-dimensional and consists of four C4NCl clusters and two HgCl2 ribbons oriented in the (1, 0, 0) direction. In two of the C4NCl clusters, there are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a single-bond geometry to one C1+ and one N3- atom. The C–C bond length is 1.29 Å. The C–N bond length is 1.27 Å. In the second C1+ site, C1+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.21 Å. In the third C1+ site, C1+ is bonded in a linear geometry to two C1+ atoms. The C–C bond length is 1.26 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one C1+ and one Cl1- atom. The C–Cl bond length is 1.61 Å. N3- is bonded in a linear geometry to two C1+ atoms. Cl1- is bonded in a single-bond geometry to one C1+ atom. In two of the C4NCl clusters, there are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.21 Å. In the second C1+ site, C1+ is bonded in a distorted single-bond geometry to one C1+ and one N3- atom. The C–C bond length is 1.29 Å. The C–N bond length is 1.26 Å. In the third C1+ site, C1+ is bonded in a distorted single-bond geometry to one C1+ and one Cl1- atom. The C–C bond length is 1.26 Å. The C–Cl bond length is 1.60 Å. In the fourth C1+ site, C1+ is bonded in a linear geometry to two C1+ atoms. N3- is bonded in a linear geometry to two C1+ atoms. Cl1- is bonded in a single-bond geometry to one C1+ atom. In each HgCl2 ribbon, there are two inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a distorted T-shaped geometry to three Cl1- atoms. There are two shorter (2.35 Å) and one longer (3.16 Å) Hg–Cl bond lengths. In the second Hg2+ site, Hg2+ is bonded in a 3-coordinate geometry to three Cl1- atoms. There are a spread of Hg–Cl bond distances ranging from 2.30–3.14 Å. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Hg2+ atom. In the second Cl1- site, Cl1- is bonded in a distorted L-shaped geometry to two Hg2+ atoms. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Hg2+ atom. In the fourth Cl1- site, Cl1- is bonded in a distorted water-like geometry to two Hg2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Direct imaging of electron density with a scanning transmission electron microscope

Abstract Recent studies of secondary electron (SE) emission in scanning transmission electron microscopes suggest that material’s properties such as electrical conductivity, connectivity, and work function can be probed with atomic scale resolution using a technique known as secondary electron e-beam-induced current (SEEBIC). Here, we apply the SEEBIC imaging technique to a stacked 2D heterostructure device to reveal the spatially resolved electron density of an encapsulated WSe 2 layer. We find that the double Se lattice site shows higher emission than the W site, which is at odds with first-principles modelling of valence ionization of an isolated WSe 2 cluster. These results illustrate that atomic level SEEBIC contrast within a single material is possible and that an enhanced understanding of atomic scale SE emission is required to account for the observed contrast. In turn, this suggests that, in the future, subtle information about interlayer bonding and the effect on electron orbitals could be directly revealed with this technique.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Defect Production and Microstructural Feature Impact for Radiation Damage in Additively Manufactured 316 Stainless Steel

This milestone presents multi-scale modeling research results for additively manufactured 316 stainless steel. A combination of phase field, cluster dynamics, molecular dynamics, and density functional theory with machine learning is used, allowing for predictions of radiation-driven microstructural evolution in additively manufactured 316 stainless steel over a range of temperatures, damage rates, neutron spectra, and microstructures, and supporting the development of combined ion and neutron irradiation for material qualification. Informed by ion irradiation and neutron irradiation results across the Advanced Materials and Manufacturing Technologies program, we investigate the unique aspects of radiation-driven microstructure evolution in additively manufactured 316 stainless steel. In particular, we focus on understanding the impact of carbon concentration (varying, for example, between the 316L and 316H standards) on void formation; radiation-induced segregation at dislocation cells and grain boundaries; and the evolution of dislocation loops and network dislocation populations. We find that the unique characteristics of the additively manufactured microstructures must be accounted for in understanding the evolution of dislocation populations under thermal and irradiation conditions, such as the variation in sink strengths arising due to the variation in dislocation density. We also find that the radiation-induced segregation of Cr and Ni to grain boundaries and cell walls differs due to the differences in their defect sink biases. We also find that increasing the Ni content can slow vacancy diffusion, which may provide a mechanism for the observed reduction in transient swelling rate for austenitic Fe-Cr-Ni alloys with increasing Ni content. In addition, ion irradiations have shown that increasing carbon content in 316 SS results in a larger population of smaller voids, suggesting reduced vacancy diffusion. Our results show that the carbon content of additively manufactured 316 SS has a significant impact on the migration rate of defect clusters. The presence of carbon atoms results in carbon-vacancy trapping, significantly reducing the diffusion rate of vacancies. Carbon atoms may also be trapped near the surface of a void, which may reduce void growth by trapping vacancies that diffuse toward the void.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2020

Materials Data on S4N5F by Materials Project

N5S4F is alpha-like structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four N5S4F clusters. In two of the N5S4F clusters, there are five inequivalent N+1.80+ sites. In the first N+1.80+ site, N+1.80+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.60 Å) and one longer (1.65 Å) N–S bond length. In the second N+1.80+ site, N+1.80+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.59 Å) and one longer (1.65 Å) N–S bond length. In the third N+1.80+ site, N+1.80+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.56 Å) and one longer (1.73 Å) N–S bond length. In the fourth N+1.80+ site, N+1.80+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.56 Å) and one longer (1.72 Å) N–S bond length. In the fifth N+1.80+ site, N+1.80+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.63 Å) and one longer (1.64 Å) N–S bond length. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a trigonal non-coplanar geometry to three N+1.80+ atoms. In the second S2- site, S2- is bonded in a trigonal non-coplanar geometry to two N+1.80+ and one F1- atom. The S–F bond length is 1.73 Å. In the third S2- site, S2- is bonded in a trigonal non-coplanar geometry to three N+1.80+ atoms. In the fourth S2- site, S2- is bonded in a bent 120 degrees geometry to two N+1.80+ atoms. F1- is bonded in a single-bond geometry to one S2- atom. In two of the N5S4F clusters, there are five inequivalent N+1.80+ sites. In the first N+1.80+ site, N+1.80+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.56 Å) and one longer (1.73 Å) N–S bond length. In the second N+1.80+ site, N+1.80+ is bonded in a bent 120 degrees geometry to two S2- atoms. Both N–S bond lengths are 1.64 Å. In the third N+1.80+ site, N+1.80+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.60 Å) and one longer (1.64 Å) N–S bond length. In the fourth N+1.80+ site, N+1.80+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.60 Å) and one longer (1.64 Å) N–S bond length. In the fifth N+1.80+ site, N+1.80+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.56 Å) and one longer (1.74 Å) N–S bond length. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a trigonal non-coplanar geometry to three N+1.80+ atoms. In the second S2- site, S2- is bonded in a trigonal non-coplanar geometry to two N+1.80+ and one F1- atom. The S–F bond length is 1.70 Å. In the third S2- site, S2- is bonded in a trigonal non-coplanar geometry to three N+1.80+ atoms. In the fourth S2- site, S2- is bonded in a bent 120 degrees geometry to two N+1.80+ atoms. F1- is bonded in a single-bond geometry to one S2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on S3N3Cl3O by Materials Project

N3S3OCl3 is alpha boron-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of eight N3S3OCl3 clusters. In four of the N3S3OCl3 clusters, there are three inequivalent N+3.67+ sites. In the first N+3.67+ site, N+3.67+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.58 Å) and one longer (1.62 Å) N–S bond length. In the second N+3.67+ site, N+3.67+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.58 Å) and one longer (1.62 Å) N–S bond length. In the third N+3.67+ site, N+3.67+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.60 Å) and one longer (1.61 Å) N–S bond length. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a trigonal non-coplanar geometry to two N+3.67+ and one Cl1- atom. The S–Cl bond length is 2.16 Å. In the second S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to two N+3.67+ and one Cl1- atom. The S–Cl bond length is 2.16 Å. In the third S2- site, S2- is bonded in a distorted tetrahedral geometry to two N+3.67+, one O2-, and one Cl1- atom. The S–O bond length is 1.43 Å. The S–Cl bond length is 2.05 Å. O2- is bonded in a single-bond geometry to one S2- atom. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one S2- atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one S2- atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one S2- atom. In four of the N3S3OCl3 clusters, there are three inequivalent N+3.67+ sites. In the first N+3.67+ site, N+3.67+ is bonded in a bent 120 degrees geometry to two S2- atoms. Both N–S bond lengths are 1.61 Å. In the second N+3.67+ site, N+3.67+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.59 Å) and one longer (1.62 Å) N–S bond length. In the third N+3.67+ site, N+3.67+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.59 Å) and one longer (1.63 Å) N–S bond length. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a trigonal non-coplanar geometry to two N+3.67+ and one Cl1- atom. The S–Cl bond length is 2.14 Å. In the second S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to two N+3.67+ and one Cl1- atom. The S–Cl bond length is 2.14 Å. In the third S2- site, S2- is bonded in a distorted tetrahedral geometry to two N+3.67+, one O2-, and one Cl1- atom. The S–O bond length is 1.43 Å. The S–Cl bond length is 2.05 Å. O2- is bonded in a single-bond geometry to one S2- atom. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one S2- atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one S2- atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one S2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Probing the atomically diffuse interfaces in Pd@Pt core-shell nanoparticles in three dimensions

Deciphering the three-dimensional atomic structure of solid-solid interfaces in core-shell nanomaterials is the key to understand their catalytical, optical and electronic properties. Here, we probe the three-dimensional atomic structures of palladium-platinum core-shell nanoparticles at the single-atom level using atomic resolution electron tomography. We quantify the rich structural variety of core-shell nanoparticles with heteroepitaxy in 3D at atomic resolution. Instead of forming an atomically-sharp boundary, the core-shell interface is found to be atomically diffuse with an average thickness of 4.2 Å, irrespective of the particle’s morphology or crystallographic texture. The high concentration of Pd in the diffusive interface is highly related to the free Pd atoms dissolved from the Pd seeds, which is confirmed by atomic images of Pd and Pt single atoms and sub-nanometer clusters using cryogenic electron microscopy. These results advance our understanding of core-shell structures at the fundamental level, providing potential strategies into precise nanomaterial manipulation and chemical property regulation.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2023

Relativistic Effects From Coupled-Cluster Theory

We discuss the theory and computational challenges of the relativistic coupled-cluster methods. Example calculations of heavy-atom-containing molecules are then presented to demonstrate the importance of scalar-relativistic, spin-orbit coupling, and electron-correlation effects on molecular properties as well as the applicability and usefulness of relativistic coupled-cluster methods in calculations aiming at high-accuracy results. Here, a unique applicability of the spinor-based relativistic coupled-cluster methods is also highlighted using the calculations of open shell actinide-containing small molecules. As a result, a summary is given together with an outlook into future developments.

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

Materials Data on RbB10H9 by Materials Project

Rb(BH)7HB2BH crystallizes in the orthorhombic Pna2_1 space group. The structure is zero-dimensional and consists of eight boranediylradical molecules, eight HB2 clusters, and four Rb(BH)7 clusters. In each HB2 cluster, there are two inequivalent B+0.60- sites. In the first B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.32 Å. In the second B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.32 Å. H+0.56+ is bonded in a water-like geometry to two B+0.60- atoms. In each Rb(BH)7 cluster, there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 8-coordinate geometry to eight H+0.56+ atoms. There are a spread of Rb–H bond distances ranging from 2.85–3.16 Å. In the second Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven H+0.56+ atoms. There are a spread of Rb–H bond distances ranging from 2.91–3.20 Å. There are fourteen inequivalent B+0.60- sites. In the first B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.19 Å. In the second B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the third B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the fourth B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the fifth B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the sixth B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the seventh B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the eighth B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the ninth B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the tenth B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the eleventh B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the twelfth B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the thirteenth B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.20 Å. In the fourteenth B+0.60- site, B+0.60- is bonded in a distorted single-bond geometry to one H+0.56+ atom. The B–H bond length is 1.19 Å. There are fourteen inequivalent H+0.56+ sites. In the first H+0.56+ site, H+0.56+ is bonded in a distorted single-bond geometry to one Rb1+ and one B+0.60- atom. In the second H+0.56+ site, H+0.56+ is bonded in a distorted single-bond geometry to one Rb1+ and one B+0.60- atom. In the third H+0.56+ site, H+0.56+ is bonded in a single-bond geometry to two Rb1+ and one B+0.60- atom. In the fourth H+0.56+ site, H+0.56+ is bonded in a single-bond geometry to one Rb1+ and one B+0.60- atom. In the fifth H+0.56+ site, H+0.56+ is bonded in a single-bond geometry to one Rb1+ and one B+0.60- atom. In the sixth H+0.56+ site, H+0.56+ is bonded in a distorted single-bond geometry to one Rb1+ and one B+0.60- atom. In the seventh H+0.56+ site, H+0.56+ is bonded in a single-bond geometry to one Rb1+ and one B+0.60- atom. In the eighth H+0.56+ site, H+0.56+ is bonded in a single-bond geometry to one Rb1+ and one B+0.60- atom. In the ninth H+0.56+ site, H+0.56+ is bonded in a single-bond geometry to one Rb1+ and one B+0.60- atom. In the tenth H+0.56+ site, H+0.56+ is bonded in a single-bond geometry to one Rb1+ and one B+0.60- atom. In the eleventh H+0.56+ site, H+0.56+ is bonded in a distorted single-bond geometry to one Rb1+ and one B+0.60- atom. In the twelfth H+0.56+ site, H+0.56+ is bonded in a distorted single-bond geometry to one Rb1+ and one B+0.60- atom. In the thirteenth H+0.56+ site, H+0.56+ is bonded in a distorted single-bond geometry to one Rb1+ and one B+0.60- atom. In the fourteenth H+0.56+ site, H+0.56+ is bonded in a single-bond geometry to one Rb1+ and one B+0.60- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Exotic bonding interactions and coexistence of chemically distinct periodic lattice distortions in the charge density wave compound TaTe2

The superstructure of TaTe 2 is examined by total high-energy x-ray scattering and large-scale structure modeling over a broad temperature range. At room temperature, it features double zigzag chains of Ta atoms exhibiting metallic bonding. The chains are sandwiched between planes of weakly interacting Te atoms. Below 170 K, the chains appear broken to “butterflylike” clusters and single zigzag chains of covalently bonded Te atoms emerge while Ta-Te interactions remain largely ionic. This is a rare example of a charge density wave compound stabilized by bonding that is a mix of covalent, ionic, and metallic character giving rise to chemically distinct periodic lattice distortions. We argue that the formation of periodic lattice distortions in the Te sublattice in addition to those in the Ta sublattice favors charge delocalization, which may explain the unusually diminished resistivity and increased magnetic susceptibility exhibited by the low-temperature charge density wave phase of TaTe 2 . The effect may be common for 5d transition metal chalcogenides containing Te because of the extended electronic orbitals of the constituent atoms.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2020

Materials Data on NaH18C9I(NO)3 by Materials Project

(Na2C9H14(NO)3)2(C3NH6O)4(C3NH3O)2(H2)7(I)4 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one 45358-43-8 molecule; two hydriodic acid molecules; four hydrogen molecules; one n,n-dimethylformamide molecule; one C3NH6O cluster; and one Na2C9H14(NO)3 cluster. In the C3NH6O cluster, there are three inequivalent C+0.33- sites. In the first C+0.33- site, C+0.33- is bonded in a trigonal planar geometry to one N3-, one H1+, and one O2- atom. The C–N bond length is 1.46 Å. The C–H bond length is 1.11 Å. The C–O bond length is 1.22 Å. In the second C+0.33- site, C+0.33- is bonded in a tetrahedral geometry to one N3- and three H1+ atoms. The C–N bond length is 1.47 Å. There are a spread of C–H bond distances ranging from 1.11–1.31 Å. In the third C+0.33- site, C+0.33- is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.32 Å. N3- is bonded in a trigonal planar geometry to three C+0.33- atoms. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one H1+ atom. The H–H bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a distorted bent 120 degrees geometry to one C+0.33- and one H1+ atom. In the fifth H1+ site, H1+ is bonded in a bent 120 degrees geometry to one C+0.33- and one H1+ atom. The H–H bond length is 0.92 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one H1+ atom. O2- is bonded in a single-bond geometry to one C+0.33- atom. In the Na2C9H14(NO)3 cluster, there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–2.53 Å. In the second Na1+ site, Na1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 2.27–2.84 Å. There are nine inequivalent C+0.33- sites. In the first C+0.33- site, C+0.33- is bonded in a tetrahedral geometry to one N3- and three H1+ atoms. The C–N bond length is 1.50 Å. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. In the second C+0.33- site, C+0.33- is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.32 Å. In the third C+0.33- site, C+0.33- is bonded in a distorted single-bond geometry to one C+0.33- and one N3- atom. The C–C bond length is 1.56 Å. The C–N bond length is 1.32 Å. In the fourth C+0.33- site, C+0.33- is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.46 Å. All C–H bond lengths are 1.10 Å. In the fifth C+0.33- site, C+0.33- is bonded in a trigonal planar geometry to one N3-, one H1+, and one O2- atom. The C–N bond length is 1.39 Å. The C–H bond length is 1.11 Å. The C–O bond length is 1.23 Å. In the sixth C+0.33- site, C+0.33- is bonded in a distorted trigonal planar geometry to one C+0.33-, one N3-, and two H1+ atoms. The C–N bond length is 1.44 Å. There is one shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. In the seventh C+0.33- site, C+0.33- is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.46 Å. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. In the eighth C+0.33- site, C+0.33- is bonded in a trigonal planar geometry to one N3-, one H1+, and one O2- atom. The C–N bond length is 1.44 Å. The C–H bond length is 1.11 Å. The C–O bond length is 1.23 Å. In the ninth C+0.33- site, C+0.33- is bonded in a trigonal planar geometry to one N3-, one H1+, and one O2- atom. The C–N bond length is 1.33 Å. The C–H bond length is 1.10 Å. The C–O bond length is 1.27 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal planar geometry to three C+0.33- atoms. In the second N3- site, N3- is bonded in a 3-coordinate geometry to three C+0.33- atoms. In the third N3- site, N3- is bonded in a trigonal planar geometry to three C+0.33- atoms. There are thirteen inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the thirteenth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+ and one C+0.33- atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two Na1+ and one C+0.33- atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Na1+ and one C+0.33- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ni2C5(Cl2O)2 by Materials Project

Ni2C2O2Cl(CCl)3 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of twelve chloromethane molecules and four Ni2C2O2Cl clusters. In two of the Ni2C2O2Cl clusters, there are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded in a distorted L-shaped geometry to one C+0.80+ and one Cl1- atom. The Ni–C bond length is 1.79 Å. The Ni–Cl bond length is 2.25 Å. In the second Ni2+ site, Ni2+ is bonded in a distorted L-shaped geometry to one C+0.80+ and one Cl1- atom. The Ni–C bond length is 1.80 Å. The Ni–Cl bond length is 2.25 Å. There are two inequivalent C+0.80+ sites. In the first C+0.80+ site, C+0.80+ is bonded in a distorted single-bond geometry to one Ni2+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C+0.80+ site, C+0.80+ is bonded in a distorted single-bond geometry to one Ni2+ and one O2- atom. The C–O bond length is 1.15 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+0.80+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+0.80+ atom. Cl1- is bonded in a bent 120 degrees geometry to two Ni2+ atoms. In two of the Ni2C2O2Cl clusters, there are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded in a distorted water-like geometry to one C+0.80+ and one Cl1- atom. The Ni–C bond length is 1.80 Å. The Ni–Cl bond length is 2.25 Å. In the second Ni2+ site, Ni2+ is bonded in a distorted L-shaped geometry to one C+0.80+ and one Cl1- atom. The Ni–C bond length is 1.80 Å. The Ni–Cl bond length is 2.25 Å. There are two inequivalent C+0.80+ sites. In the first C+0.80+ site, C+0.80+ is bonded in a distorted single-bond geometry to one Ni2+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C+0.80+ site, C+0.80+ is bonded in a distorted single-bond geometry to one Ni2+ and one O2- atom. The C–O bond length is 1.15 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+0.80+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+0.80+ atom. Cl1- is bonded in a bent 120 degrees geometry to two Ni2+ atoms.

36 MATERIALS SCIENCE↗
NASA NTRS2012

Fischer-Tropsch Cobalt Catalyst Improvements with the Presence of TiO2, La2O3, and ZrO2 on an Alumina Support

The objective of this study was to evaluate the effect of titanium oxide, lanthanum oxide, and zirconium oxide on alumina supported cobalt catalysts. The hypothesis was that the presence of lanthanum oxide, titanium oxide, and zirconium oxide would reduce the interaction between cobalt and the alumina support. This was of interest because an optimized weakened interaction could lead to the most advantageous cobalt dispersion, particle size, and reducibility. The presence of these oxides on the support were investigated using a wide range of characterization techniques such as SEM, nitrogen adsorption, x-ray diffraction (XRD), temperature programmed reduction (TPR), temperature programmed reduction after reduction (TPR-AR), and hydrogen chemisorptions/pulse reoxidation. Results indicated that both La2O3 and TiO2 doped supports facilitated the reduction of cobalt oxide species in reference to pure alumina supported cobalt catalysts, however further investigation is needed to determine the effect of ZrO2 on the reduction profile. Results showed an increased corrected cluster size for all three doped supported catalysts in comparison to their reference catalysts. The increase in reduction and an increase in the cluster size led to the conclusion that the support-metal interaction weakened by the addition of TiO2 and La2O3. It is also likely that the interaction decreased upon presence of ZrO2 on the alumina, but further research is necessary. Preliminary results have indicated that the alumina-supported catalysts with titanium oxide and lanthanum oxide present are of interest because of the weakened cobalt support interaction. These catalysts showed an increased extent of reduction, therefore more metallic cobalt is present on the support. However, whether or not there is more cobalt available to participate in the Fischer-Tropsch synthesis reaction (cobalt surface atoms) depends also on the cluster size. On one hand, increasing cluster size alone tends to decrease the active site density; on the other hand, by increasing the size of the cobalt clusters, there is less likelihood of forming oxidized cobalt complexes (cobalt aluminate) during Fischer-Tropsch synthesis. Thus, from the standpoint of stability, improving the extent of reduction while increasing the particle size slightly may be beneficial for maintaining the sites, even if there is a slight decrease in overall initial active site density.

Klettlinger, Jennifer Lindsey Suder↗
DOE OSTI2025

Monolayer TiS 2 Nanosheets on Au(111)–Structural Characterization and Effect of Edge Stability for Shape Control

Transition metal dichalcogenides are promising alternatives to noble metal catalysts, e.g., for (photo-)activation of greenhouse gases or hydrogenations. Herein, a direct synthetic route for 2D TiS 2 nanosheets on Au(111) by titanium deposition in the presence of a mild, organic, non-oxidizing sulfur source is presented. High-resolution scanning tunneling microscopy (STM) is used to gain atomic-level insights into the TiS 2 nanosheet morphology. In contrast to the literature, this protocol gains mostly hexagonal and truncated triangular nanosheets with an increased edge contrast in STM, analog to metallic edge states in MoS 2 . Synchrotron-based photoelectron spectroscopy allows insights into compositional details, specifically to distinguish different S sites on the TiS 2 sheets and other S species on the sample. Further, a minimum size is identified (9 S atoms side length), which underlines the importance of moiré reconstructions for stress relief. The TiS 2 sheets coexist with [Au]Ti 1 S 3 clusters, in which a single gold atom is alloyed into the surface and capped by three S atoms. Together with the finding of a critical sheet size, this points toward on-surface Ostwald ripening as a relevant process in the sheet formation. Ab-initio calculations (density functional theory) underscore that the chemical potential of S is an essential descriptor to maintain shape control.

2D nanomaterials↗
DOE OSTI2025

Development of an interatomic potential for the Ta–Li system

A new interatomic potential for the Ta–Li system is introduced to facilitate the study of phase stability, mechanical properties and non-equilibrium dynamics after Li implantation in Ta. Here, this potential is based on a generalization of the embedded atom method (GEAM) and includes contributions from embedding energy, explicit two- and three-body interactions, and nonlocal many-body interaction terms. The parameters of the potential are optimized using energies and atomic forces for a wide range of configurations obtained from ab initio density functional theory (DFT) calculations. The potential is rigorously validated across a range of physical properties, including elastic constants, equations of state, phonon dispersion curves, point defect properties, and melting temperatures for different compositions. Although our potential is trained on a small dataset, its accuracy is comparable to that of available machine learning potentials for Li and Ta. Our simulations show that at temperatures below 500 K, Li atoms in Ta–Li alloys form clusters separated by Ta-rich domains, and we find no evidence of ordered phase formation. For Li concentrations below a few percent, Li atoms preferentially segregate to surfaces and grain boundaries. However, in alloys containing more than ~10% Li, the accumulation of Li in symmetric-tilt grain boundaries can lead to one of the following effects: formation of amorphous-like regions, changes in grain boundary structural units, or lateral movement of the grain boundary.

GEAM potential↗
DOE OSTI2020

Prediction of Structures and Atomization Energies of Coinage Metals, (M)n, n < 20: Extrapolation of Normalized Clustering Energies to Predict the Cohesive Energy

The geometries of the group 11 coinage metals (n = 2-20) were optimized to determine the lowest energy isomers for each cluster size, singlets for even numbers and doublets for odd numbers. For copper and silver, 2-D (planar) geometries were favored up to n = 6. For gold, 2D (planar) geometries were favored up to n = 13. Normalized clustering energies were plotted as a function of cluster size (n-1/3, for n = 4-20) with various DFT functionals and the CCSD(T)-F12b method and were extrapolated to predict the bulk cohesive energy. In the case of copper and silver, there is excellent agreement between the cohesive energies predicted at the CCSD(T)-F12b level of theory and the experimental values. For gold, the CCSD(T)-F12b values needed to be corrected for spin-orbit relativistic effects to obtain good agreement with experiment. Electronic properties including the HOMO-LUMO gaps for the even clusters and the spin densities for the odd clusters were calculated. The lowest gap is predicted to occur for n = 16 where the HOMO and LUMO are very similar in shape.

Persuad, Rudradatt R.↗