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At least 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on ThNi(N3O13)2 by Materials Project

Th(NO3)6NiO6O2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four water molecules, two NiO6 clusters, and two Th(NO3)6 clusters. In each NiO6 cluster, Ni is bonded in an octahedral geometry to six O atoms. There are a spread of Ni–O bond distances ranging from 1.82–1.86 Å. There are three inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Ni atom. In the second O site, O is bonded in a single-bond geometry to one Ni atom. In the third O site, O is bonded in a single-bond geometry to one Ni atom. In each Th(NO3)6 cluster, Th is bonded in a cuboctahedral geometry to twelve O atoms. There are a spread of Th–O bond distances ranging from 2.54–2.65 Å. There are three inequivalent N sites. In the first N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.25–1.28 Å. In the second N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.22–1.30 Å. In the third N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.26–1.28 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the second O site, O is bonded in a single-bond geometry to one N atom. In the third O site, O is bonded in a single-bond geometry to one N atom. In the fourth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the fifth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the sixth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the seventh O site, O is bonded in a single-bond geometry to one N atom. In the eighth O site, O is bonded in a distorted water-like geometry to one Th and one N atom. In the ninth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ThZn(N3O13)2 by Materials Project

Th(NO3)6ZnO6O2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four water molecules, two Th(NO3)6 clusters, and two zinc;hexahydrate molecules. In each Th(NO3)6 cluster, Th is bonded in a cuboctahedral geometry to twelve O atoms. There are a spread of Th–O bond distances ranging from 2.54–2.64 Å. There are three inequivalent N sites. In the first N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.25–1.28 Å. In the second N site, N is bonded in a trigonal planar geometry to three O atoms. There is one shorter (1.22 Å) and two longer (1.29 Å) N–O bond length. In the third N site, N is bonded in a trigonal planar geometry to three O atoms. There is one shorter (1.25 Å) and two longer (1.27 Å) N–O bond length. There are nine inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the second O site, O is bonded in a single-bond geometry to one N atom. In the third O site, O is bonded in a single-bond geometry to one N atom. In the fourth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the fifth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the sixth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the seventh O site, O is bonded in a single-bond geometry to one N atom. In the eighth O site, O is bonded in a distorted water-like geometry to one Th and one N atom. In the ninth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th2SiGe by Materials Project

Th2GeSi crystallizes in the orthorhombic Pmc2_1 space group. The structure is three-dimensional. there are two inequivalent Th sites. In the first Th site, Th is bonded in a 7-coordinate geometry to three equivalent Ge and four equivalent Si atoms. There are a spread of Th–Ge bond distances ranging from 3.12–3.28 Å. There are two shorter (3.05 Å) and two longer (3.09 Å) Th–Si bond lengths. In the second Th site, Th is bonded in a 7-coordinate geometry to four equivalent Ge and three equivalent Si atoms. There are two shorter (3.07 Å) and two longer (3.09 Å) Th–Ge bond lengths. There are a spread of Th–Si bond distances ranging from 3.07–3.30 Å. Ge is bonded in a 9-coordinate geometry to seven Th and two equivalent Si atoms. Both Ge–Si bond lengths are 2.80 Å. Si is bonded in a 9-coordinate geometry to seven Th and two equivalent Ge atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Impact of Noncovalent Interactions on the Structural Chemistry of Thorium(IV)-Aquo-Chloro Complexes

Five novel tetravalent thorium (Th) compounds that consist of Th(H 2 O) x Cl y structural units were isolated from acidic aqueous solutions using a series of nitrogen-containing heterocyclic hydrogen (H) bond donors. Taken together with three previously reported phases, the compounds provide a series of monomeric Th IV complexes wherein the effects of noncovalent interactions (and H-bond donor identity) on Th structural chemistry can be examined. Seven distinct structural units of the general formulas [Th(H 2 O) x Cl 8–x ] x-4 (x = 2, 4) and [Th(H 2 O) x Cl 9–x] x-5 (x = 5–7) are described. The complexes range from chloride-deficient [Th(H 2 O) 7 Cl 2 ] 2+ to chloride-rich [Th(H 2 O) 2 Cl 6 ] 2– species, and theory was used to understand the relative energies that separate complexes within this series via the stepwise chloride addition to an aquated Th cation. Electronic structure theory predicted the reaction energies of chloride addition and release of water through a series of transformations, generally highlighting an energetic driving force for chloride complexation. To probe the role of the counterion in the stabilization of these complexes, electrostatic potential (ESP) surfaces were calculated. Finally, the ESP surfaces indicated a dependence of the chloride distribution about the Th metal center on the pK a of the countercation, highlighting the directing effects of noncovalent interactions (e.g., Hbonding) on Th speciation.

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

Confident detection of doubly ionized thorium in the extreme Ap star CPD-62° 2717

Despite the Universe containing primordial thorium (Th) of sufficient abundance to appear in stellar spectra, detection of Th has to date been tentative and based on just a few weak and blended lines. Here, we present convincing evidence not only for the first Th detection in a magnetic chemically peculiar Ap star but also for the first detection of Th iii in a stellar spectrum. CPD-62° 2717 was initially recognized as a highly magnetized Ap star due to resolved magnetically split lines captured in H-band spectra from the SDSS/APOGEE survey. The star was subsequently pinpointed as extraordinarily peculiar when careful inspection of the H-band line content revealed the presence of five lines of Th iii, none of which are detected in the other ∼1500 APOGEE-observed Ap stars. Follow-up with the VLT + UVES confirmed a similarly peculiar optical spectrum featuring dozens of Th iii lines, among other peculiarities. Unlike past claims of Th detection, and owing to high-resolution observations of the strong (∼8–12 kG) magnetic field of CPD-62° 2717, the detection of Th iii can in this case be supported by matches between the observed and theoretical magnetic splitting patterns. Comparison of CPD-62° 2717 to stars for which Th overabundances have been previously reported (e.g. Przybylski’s Star) indicates that only for CPD-62° 2717 is the Th detection certain. Along with the focus on Th iii, we use time series measurements of the magnetic field modulus to constrain the rotation period of CPD-62° 2717 to ∼4.8 yr, thus establishing it as a new example of a superslowly rotating Ap star.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2024

First-principles determination of the phonon-point defect scattering and thermal transport due to fission products in ThO 2

This work presents the first-principles calculations of the lattice thermal conductivity degradation due to point defects in thorium dioxide using an iterative solution of the Pierels-Boltzmann transport equation. We have used the non perturbative Green’s function methodology to compute the phonon- point defect scattering rates that consider the local distortion around the point defect, including the mass difference changes, interatomic force constants, and structural relaxation near the point defects. The point defects considered in this work include the vacancy of thorium ($V$ $TH$ ) and oxygen ($V$ $O$ ), substitutions of helium ($He$ $Th$ ), krypton ($Kr$ $Th$ ), zirconium ($Zr$ $Th$ ), iodine ($I$ $Th$ ) and xenon ($Xe$ $Th$ ) in the thorium site, and the three different configurations of the Schottky defects. The results of the phonon-defect scattering rate reveal that, among all the considered intrinsic defects, the thorium vacancy and helium substitution in the thorium site scatter the phonon most due to the substantial changes in the force constant and structural distortions. The scattering of phonons due to the substitutional defects unveils that the zirconium atom scatters phonons the least, followed by xenon, iodine, krypton, and helium. This is contrary to the intuition that the scattering strength follows $He$ $Th$ > $Kr$ $Th$ > $Zr$ $Th$ > $I$ $Th$ > $Xe$ $Th$ based on the mass difference. This striking difference in the zirconium phonon scattering is due to the local chemical environment changes. Zirconium is an electropositive element with valency similar to thorium and, therefore, can bond with the oxygen atoms, thus creating less force constant variance compared to iodine, an electronegative element noble gas helium, xenon, and krypton. In conclusion, these results can serve as the benchmark for the analytical models and help the engineering-scale modeling effort for nuclear design.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th2S3 by Materials Project

Th2S3 is Stibnite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Th sites. In the first Th site, Th is bonded in a 7-coordinate geometry to eight S atoms. There are a spread of Th–S bond distances ranging from 2.87–3.48 Å. In the second Th site, Th is bonded to seven S atoms to form a mixture of distorted edge and corner-sharing ThS7 pentagonal bipyramids. There are a spread of Th–S bond distances ranging from 2.85–2.90 Å. There are three inequivalent S sites. In the first S site, S is bonded to five Th atoms to form a mixture of edge and corner-sharing STh5 square pyramids. In the second S site, S is bonded to five Th atoms to form a mixture of distorted edge and corner-sharing STh5 trigonal bipyramids. In the third S site, S is bonded in a distorted rectangular see-saw-like geometry to five Th atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ThFe5P3 by Materials Project

ThFe5P3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Th is bonded in a 8-coordinate geometry to ten Fe and six P atoms. There are a spread of Th–Fe bond distances ranging from 2.96–3.17 Å. There are a spread of Th–P bond distances ranging from 2.88–2.95 Å. There are five inequivalent Fe sites. In the first Fe site, Fe is bonded to three equivalent Th and four P atoms to form a mixture of distorted edge, corner, and face-sharing FeTh3P4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.31–2.35 Å. In the second Fe site, Fe is bonded in a 1-coordinate geometry to five P atoms. There are a spread of Fe–P bond distances ranging from 2.23–2.57 Å. In the third Fe site, Fe is bonded to three equivalent Th and four P atoms to form a mixture of distorted edge, corner, and face-sharing FeTh3P4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.31–2.40 Å. In the fourth Fe site, Fe is bonded to three equivalent Th and four P atoms to form a mixture of distorted edge, corner, and face-sharing FeTh3P4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.23–2.37 Å. In the fifth Fe site, Fe is bonded to one Th and four P atoms to form a mixture of distorted edge, corner, and face-sharing FeThP4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.14–2.25 Å. There are three inequivalent P sites. In the first P site, P is bonded in a 9-coordinate geometry to two equivalent Th and seven Fe atoms. In the second P site, P is bonded in a 9-coordinate geometry to two equivalent Th and seven Fe atoms. In the third P site, P is bonded in a 9-coordinate geometry to two equivalent Th and seven Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ThFe3 by Materials Project

ThFe3 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Th sites. In the first Th site, Th is bonded in a 12-coordinate geometry to twelve Fe atoms. There are a spread of Th–Fe bond distances ranging from 2.98–3.15 Å. In the second Th site, Th is bonded in a 6-coordinate geometry to eighteen Fe atoms. There are six shorter (2.97 Å) and twelve longer (3.28 Å) Th–Fe bond lengths. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to five Th and seven Fe atoms to form a mixture of face, edge, and corner-sharing FeTh5Fe7 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.50–2.59 Å. In the second Fe site, Fe is bonded in a 12-coordinate geometry to three equivalent Th and six equivalent Fe atoms. In the third Fe site, Fe is bonded to six equivalent Th and six equivalent Fe atoms to form FeTh6Fe6 cuboctahedra that share corners with twelve equivalent FeTh5Fe7 cuboctahedra, edges with six equivalent FeTh6Fe6 cuboctahedra, and faces with eighteen equivalent FeTh5Fe7 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th6Mg23 by Materials Project

Mg23Th6 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 1-coordinate geometry to ten Mg and three equivalent Th atoms. There are a spread of Mg–Mg bond distances ranging from 2.97–3.43 Å. All Mg–Th bond lengths are 3.71 Å. In the second Mg site, Mg is bonded to nine Mg and three equivalent Th atoms to form a mixture of distorted corner and face-sharing MgTh3Mg9 cuboctahedra. There are three shorter (2.92 Å) and three longer (3.24 Å) Mg–Mg bond lengths. All Mg–Th bond lengths are 3.45 Å. In the third Mg site, Mg is bonded to eight Mg and four equivalent Th atoms to form distorted MgTh4Mg8 cuboctahedra that share corners with twelve MgTh4Mg8 cuboctahedra and faces with sixteen MgTh3Mg9 cuboctahedra. All Mg–Th bond lengths are 3.70 Å. In the fourth Mg site, Mg is bonded in a body-centered cubic geometry to eight equivalent Mg atoms. Th is bonded in a 4-coordinate geometry to twelve Mg and four equivalent Th atoms. All Th–Th bond lengths are 3.72 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ThURe4 by Materials Project

UThRe4 is Hexagonal Laves-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. U is bonded in a 12-coordinate geometry to three equivalent U, one Th, and twelve Re atoms. All U–U bond lengths are 3.33 Å. The U–Th bond length is 3.30 Å. There are a spread of U–Re bond distances ranging from 3.12–3.20 Å. Th is bonded in a 12-coordinate geometry to one U, three equivalent Th, and twelve Re atoms. There are one shorter (3.36 Å) and two longer (3.37 Å) Th–Th bond lengths. There are a spread of Th–Re bond distances ranging from 3.19–3.24 Å. There are four inequivalent Re sites. In the first Re site, Re is bonded to six equivalent Th and six Re atoms to form ReTh6Re6 cuboctahedra that share corners with twelve ReTh3U3Re6 cuboctahedra, edges with six equivalent ReTh6Re6 cuboctahedra, and faces with twenty ReU6Re6 cuboctahedra. There are two shorter (2.77 Å) and four longer (2.78 Å) Re–Re bond lengths. In the second Re site, Re is bonded to six equivalent U and six Re atoms to form ReU6Re6 cuboctahedra that share corners with twelve ReTh3U3Re6 cuboctahedra, edges with six equivalent ReU6Re6 cuboctahedra, and faces with twenty ReTh6Re6 cuboctahedra. There are four shorter (2.70 Å) and two longer (2.71 Å) Re–Re bond lengths. In the third Re site, Re is bonded to three equivalent U, three equivalent Th, and six Re atoms to form ReTh3U3Re6 cuboctahedra that share corners with eighteen ReTh6Re6 cuboctahedra, edges with six equivalent ReTh3U3Re6 cuboctahedra, and faces with eighteen ReTh6Re6 cuboctahedra. There are a spread of Re–Re bond distances ranging from 2.66–2.80 Å. In the fourth Re site, Re is bonded to three equivalent U, three equivalent Th, and six Re atoms to form ReTh3U3Re6 cuboctahedra that share corners with eighteen ReTh6Re6 cuboctahedra, edges with six equivalent ReTh3U3Re6 cuboctahedra, and faces with eighteen ReTh6Re6 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ThMo2O11 by Materials Project

ThMo2O9O2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional and consists of four oxygen molecules and one ThMo2O9 framework. In the ThMo2O9 framework, Th is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Th–O bond distances ranging from 2.37–2.62 Å. There are two inequivalent Mo sites. In the first Mo site, Mo is bonded in a tetrahedral geometry to four O atoms. There is three shorter (1.79 Å) and one longer (1.82 Å) Mo–O bond length. In the second Mo site, Mo is bonded in a distorted tetrahedral geometry to five O atoms. There are a spread of Mo–O bond distances ranging from 1.79–2.50 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one Th and one Mo atom. In the second O site, O is bonded in a bent 150 degrees geometry to one Th and one Mo atom. In the third O site, O is bonded in a bent 150 degrees geometry to one Th and one Mo atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to one Th and one Mo atom. In the fifth O site, O is bonded in a single-bond geometry to one Mo atom. In the sixth O site, O is bonded in a 2-coordinate geometry to one Th and one Mo atom. In the seventh O site, O is bonded in a distorted bent 150 degrees geometry to one Th and one Mo atom. In the eighth O site, O is bonded in a linear geometry to one Th and one Mo atom. In the ninth O site, O is bonded in a bent 150 degrees geometry to one Th and one Mo atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th4UTe5 by Materials Project

UTh4Te5 is Heusler-like structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. U is bonded in a body-centered cubic geometry to eight equivalent Te atoms. All U–Te bond lengths are 3.31 Å. There are two inequivalent Th sites. In the first Th site, Th is bonded in a body-centered cubic geometry to eight Te atoms. There are four shorter (3.32 Å) and four longer (3.33 Å) Th–Te bond lengths. In the second Th site, Th is bonded in a body-centered cubic geometry to eight Te atoms. All Th–Te bond lengths are 3.32 Å. There are three inequivalent Te sites. In the first Te site, Te is bonded in a body-centered cubic geometry to four equivalent U and four equivalent Th atoms. In the second Te site, Te is bonded in a body-centered cubic geometry to eight Th atoms. In the third Te site, Te is bonded in a body-centered cubic geometry to eight equivalent Th atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th3In5 by Materials Project

Th3In5 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Th sites. In the first Th site, Th is bonded in a 9-coordinate geometry to nine In atoms. There are a spread of Th–In bond distances ranging from 3.19–3.61 Å. In the second Th site, Th is bonded in a 10-coordinate geometry to ten In atoms. There are a spread of Th–In bond distances ranging from 3.29–3.53 Å. There are three inequivalent In sites. In the first In site, In is bonded in a 5-coordinate geometry to five Th and four In atoms. There are two shorter (3.10 Å) and two longer (3.20 Å) In–In bond lengths. In the second In site, In is bonded in a 10-coordinate geometry to six Th and four In atoms. There are two shorter (3.01 Å) and one longer (3.36 Å) In–In bond lengths. In the third In site, In is bonded in a 9-coordinate geometry to six Th and three In atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y3Th3Mn23 by Materials Project

Th3Y3Mn23 crystallizes in the trigonal R3m space group. The structure is three-dimensional. Th is bonded in a 12-coordinate geometry to twelve Mn atoms. There are a spread of Th–Mn bond distances ranging from 2.92–3.14 Å. Y is bonded in a 12-coordinate geometry to twelve Mn atoms. There are a spread of Y–Mn bond distances ranging from 2.95–3.08 Å. There are eleven inequivalent Mn sites. In the first Mn site, Mn is bonded in a 10-coordinate geometry to two equivalent Th, one Y, and ten Mn atoms. There are a spread of Mn–Mn bond distances ranging from 2.60–2.98 Å. In the second Mn site, Mn is bonded to two equivalent Th, two equivalent Y, and eight Mn atoms to form a mixture of face and corner-sharing MnY2Th2Mn8 cuboctahedra. There are a spread of Mn–Mn bond distances ranging from 2.49–2.69 Å. In the third Mn site, Mn is bonded to two equivalent Th, two equivalent Y, and eight Mn atoms to form a mixture of face and corner-sharing MnY2Th2Mn8 cuboctahedra. There are a spread of Mn–Mn bond distances ranging from 2.43–2.65 Å. In the fourth Mn site, Mn is bonded to three equivalent Th and nine Mn atoms to form a mixture of face and corner-sharing MnTh3Mn9 cuboctahedra. There are three shorter (2.41 Å) and three longer (2.57 Å) Mn–Mn bond lengths. In the fifth Mn site, Mn is bonded in a distorted q6 geometry to one Th, two equivalent Y, and nine Mn atoms. There are a spread of Mn–Mn bond distances ranging from 2.48–2.62 Å. In the sixth Mn site, Mn is bonded in a distorted q6 geometry to three equivalent Y and nine Mn atoms. All Mn–Mn bond lengths are 2.48 Å. In the seventh Mn site, Mn is bonded to two equivalent Th, one Y, and nine Mn atoms to form a mixture of face and corner-sharing MnYTh2Mn9 cuboctahedra. There are two shorter (2.43 Å) and one longer (2.57 Å) Mn–Mn bond lengths. In the eighth Mn site, Mn is bonded in a body-centered cubic geometry to eight Mn atoms. There are a spread of Mn–Mn bond distances ranging from 2.51–2.64 Å. In the ninth Mn site, Mn is bonded in a 10-coordinate geometry to three equivalent Th and ten Mn atoms. In the tenth Mn site, Mn is bonded in a 10-coordinate geometry to one Th, two equivalent Y, and ten Mn atoms. The Mn–Mn bond length is 3.00 Å. In the eleventh Mn site, Mn is bonded in a 10-coordinate geometry to three equivalent Y and ten Mn atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ThMg(N3O13)2 by Materials Project

MgO8Th(NO3)6 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two MgO8 clusters and two Th(NO3)6 clusters. In each MgO8 cluster, Mg is bonded in a distorted octahedral geometry to six O atoms. There are two shorter (2.08 Å) and four longer (2.16 Å) Mg–O bond lengths. There are four inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two O atoms. Both O–O bond lengths are 1.31 Å. In the second O site, O is bonded in a single-bond geometry to one Mg atom. In the third O site, O is bonded in an L-shaped geometry to one Mg and one O atom. In the fourth O site, O is bonded in an L-shaped geometry to one Mg and one O atom. In each Th(NO3)6 cluster, Th is bonded in a cuboctahedral geometry to twelve O atoms. There are a spread of Th–O bond distances ranging from 2.56–2.64 Å. There are three inequivalent N sites. In the first N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.22–1.30 Å. In the second N site, N is bonded in a trigonal planar geometry to three O atoms. There is one shorter (1.25 Å) and two longer (1.27 Å) N–O bond length. In the third N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.23–1.29 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the second O site, O is bonded in a single-bond geometry to one N atom. In the third O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the fourth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the fifth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the sixth O site, O is bonded in a single-bond geometry to one N atom. In the seventh O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the eighth O site, O is bonded in a single-bond geometry to one N atom. In the ninth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ce3Th3Si4 by Materials Project

Th3Ce3Si4 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent Th sites. In the first Th site, Th is bonded in a 6-coordinate geometry to six Si atoms. There are two shorter (3.07 Å) and four longer (3.13 Å) Th–Si bond lengths. In the second Th site, Th is bonded in a 6-coordinate geometry to six Si atoms. There are two shorter (3.08 Å) and four longer (3.13 Å) Th–Si bond lengths. There are two inequivalent Ce sites. In the first Ce site, Ce is bonded in a distorted rectangular see-saw-like geometry to four Si atoms. There are a spread of Ce–Si bond distances ranging from 3.09–3.15 Å. In the second Ce site, Ce is bonded in a distorted hexagonal planar geometry to six Si atoms. There are two shorter (3.05 Å) and four longer (3.12 Å) Ce–Si bond lengths. There are three inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to six Th, two equivalent Ce, and one Si atom. The Si–Si bond length is 2.50 Å. In the second Si site, Si is bonded in a 9-coordinate geometry to four equivalent Th, four Ce, and one Si atom. In the third Si site, Si is bonded in a 9-coordinate geometry to four Th, four Ce, and one Si atom. The Si–Si bond length is 2.47 Å.

36 MATERIALS SCIENCE↗