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DOE OSTI2020

Materials Data on TbTh by Materials Project

ThTb 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 to six equivalent Th and six Tb atoms to form ThTb6Th6 cuboctahedra that share corners with twelve ThTb6Th6 cuboctahedra, edges with twelve ThTb6Th6 cuboctahedra, edges with twelve TbTb6Th6 cuboctahedra, faces with six equivalent ThTb6Th6 cuboctahedra, and faces with twelve TbTb6Th6 cuboctahedra. All Th–Th bond lengths are 3.55 Å. All Th–Tb bond lengths are 3.56 Å. In the second Th site, Th is bonded to ten equivalent Th and six Tb atoms to form ThTb6Th10 cuboctahedra that share corners with ten TbTb6Th6 cuboctahedra, corners with twelve ThTb6Th6 cuboctahedra, edges with eight TbTb6Th6 cuboctahedra, edges with sixteen ThTb6Th6 cuboctahedra, faces with sixteen equivalent ThTb6Th10 cuboctahedra, and faces with eighteen TbTb6Th6 cuboctahedra. There are a spread of Th–Th bond distances ranging from 3.55–7.11 Å. All Th–Tb bond lengths are 3.56 Å. There are three inequivalent Tb sites. In the first Tb site, Tb is bonded to six equivalent Th and six equivalent Tb atoms to form TbTb6Th6 cuboctahedra that share corners with twelve TbTb6Th6 cuboctahedra, edges with twelve equivalent ThTb6Th6 cuboctahedra, edges with twelve TbTb6Th6 cuboctahedra, faces with six equivalent TbTb6Th6 cuboctahedra, and faces with twelve equivalent ThTb6Th6 cuboctahedra. All Tb–Tb bond lengths are 3.55 Å. In the second Tb site, Tb is bonded to six Th and six equivalent Tb atoms to form TbTb6Th6 cuboctahedra that share corners with five equivalent ThTb6Th10 cuboctahedra, corners with twelve TbTb6Th6 cuboctahedra, edges with ten ThTb6Th6 cuboctahedra, edges with twelve TbTb6Th6 cuboctahedra, faces with six equivalent TbTb6Th6 cuboctahedra, and faces with fifteen ThTb6Th6 cuboctahedra. All Tb–Th bond lengths are 3.56 Å. All Tb–Tb bond lengths are 3.55 Å. In the third Tb site, Tb is bonded to six Th and six equivalent Tb atoms to form TbTb6Th6 cuboctahedra that share corners with five equivalent ThTb6Th10 cuboctahedra, corners with twelve TbTb6Th6 cuboctahedra, edges with ten ThTb6Th6 cuboctahedra, edges with twelve TbTb6Th6 cuboctahedra, faces with six equivalent TbTb6Th6 cuboctahedra, and faces with fifteen ThTb6Th6 cuboctahedra. All Tb–Tb bond lengths are 3.55 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Probing the Electronic Structure of a Thorium Nitride Complex by Solid-State 15N NMR Spectroscopy

The solid-state 15N NMR powder spectra of the thorium nitride complex, [K(18-crown-6)(THF)2][(R2N)3Th(m-15N)(Th(NR2)3] ([K][1-15N], R = SiMe3), and the thorium amide complex, [Th(NR2)3(15NH2)] (2-15N) were recorded. The spectrum for [K][1-15N] represents the first reported solid-state 15N NMR data for an actinide nitride complex. The experimentally measured tensor spans are 847 ppm for [K][1-15N] and 237 ppm for 2-15N. Both shielding tensors exhibit a near-zero asymmetry parameter, which for [K][1-15N] is consistent with a local rotational symmetry of its 15N-labelled nitride ligand. For 2-15N, the lack of asymmetry can be rationalized by a quasi-free Th-NH2 bond rotation in the solid-state. DFT calculations overestimate the tensor span somewhat for [K][1-15N], but provide isotropic shifts in good agreement with both the solid-state and solution values for both complexes. Natural localized molecular orbital (NLMO) analyses of the nuclear shielding reveal that the larger tensor span in [K][1-15N] vs. 2-15N is primarily a consequence of more pronounced covalency of the N-Th bonds, and large spin-orbit coupling due to significant Th 5f orbital contribution to those bonds, impacting the principal components of the shielding tensor perpendicular to the Th-N-Th axis. Overall, our analysis confirms the involvement of the 5f orbitals in Th-N multiple bonds, and further demonstrates the value of solid-state NMR spectroscopy for interrogating actinide-ligand bonding.

actinides, covalent bonding, Nuclear Magnetic Reso↗
DOE OSTI2020

Materials Data on AcTh3 by Materials Project

Th3Ac is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are three inequivalent Th sites. In the first Th site, Th is bonded to eight Th and four equivalent Ac atoms to form ThAc4Th8 cuboctahedra that share corners with four equivalent AcTh12 cuboctahedra, corners with fourteen ThAc4Th8 cuboctahedra, edges with six equivalent AcTh12 cuboctahedra, edges with twelve ThAc4Th8 cuboctahedra, faces with four equivalent AcTh12 cuboctahedra, and faces with sixteen ThAc4Th8 cuboctahedra. There are a spread of Th–Th bond distances ranging from 3.54–3.78 Å. There are two shorter (3.66 Å) and two longer (3.72 Å) Th–Ac bond lengths. In the second Th site, Th is bonded to eight equivalent Th and four equivalent Ac atoms to form ThAc4Th8 cuboctahedra that share corners with four equivalent AcTh12 cuboctahedra, corners with fourteen ThAc4Th8 cuboctahedra, edges with six equivalent AcTh12 cuboctahedra, edges with twelve equivalent ThAc4Th8 cuboctahedra, faces with four equivalent AcTh12 cuboctahedra, and faces with sixteen ThAc4Th8 cuboctahedra. There are two shorter (3.66 Å) and two longer (3.72 Å) Th–Ac bond lengths. In the third Th site, Th is bonded to eight equivalent Th and four equivalent Ac atoms to form ThAc4Th8 cuboctahedra that share corners with four equivalent AcTh12 cuboctahedra, corners with fourteen ThAc4Th8 cuboctahedra, edges with six equivalent AcTh12 cuboctahedra, edges with twelve equivalent ThAc4Th8 cuboctahedra, faces with four equivalent AcTh12 cuboctahedra, and faces with sixteen ThAc4Th8 cuboctahedra. There are two shorter (3.66 Å) and two longer (3.72 Å) Th–Ac bond lengths. Ac is bonded to twelve Th atoms to form AcTh12 cuboctahedra that share corners with six equivalent AcTh12 cuboctahedra, corners with twelve ThAc4Th8 cuboctahedra, edges with eighteen ThAc4Th8 cuboctahedra, faces with eight equivalent AcTh12 cuboctahedra, and faces with twelve ThAc4Th8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th5C by Materials Project

CTh5 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Th sites. In the first Th site, Th is bonded to twelve Th atoms to form ThTh12 cuboctahedra that share corners with nine equivalent ThTh12 cuboctahedra, corners with six equivalent CTh6 octahedra, edges with fifteen ThTh12 cuboctahedra, faces with twelve ThTh12 cuboctahedra, and a faceface with one CTh6 octahedra. The corner-sharing octahedral tilt angles are 44°. There are a spread of Th–Th bond distances ranging from 3.58–3.71 Å. In the second Th site, Th is bonded to twelve Th atoms to form a mixture of edge, corner, and face-sharing ThTh12 cuboctahedra. All Th–Th bond lengths are 3.59 Å. In the third Th site, Th is bonded in a distorted T-shaped geometry to three equivalent Th and three equivalent C atoms. All Th–C bond lengths are 2.57 Å. C is bonded to six equivalent Th atoms to form CTh6 octahedra that share corners with twelve equivalent ThTh12 cuboctahedra, edges with six equivalent CTh6 octahedra, and faces with two equivalent ThTh12 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th2Fe14B by Materials Project

Th2Fe14B crystallizes in the tetragonal P4_2/mnm 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 sixteen Fe and two equivalent B atoms. There are a spread of Th–Fe bond distances ranging from 3.03–3.25 Å. Both Th–B bond lengths are 3.22 Å. In the second Th site, Th is bonded in a 1-coordinate geometry to sixteen Fe and one B atom. There are a spread of Th–Fe bond distances ranging from 3.03–3.35 Å. The Th–B bond length is 2.86 Å. There are six inequivalent Fe sites. In the first Fe site, Fe is bonded in a distorted q6 geometry to two Th and ten Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.38–2.65 Å. In the second Fe site, Fe is bonded to four Th and eight Fe atoms to form FeTh4Fe8 cuboctahedra that share corners with twelve FeTh4Fe8 cuboctahedra and faces with four equivalent FeTh3Fe9 cuboctahedra. All Fe–Fe bond lengths are 2.56 Å. In the third Fe site, Fe is bonded in a distorted L-shaped geometry to two equivalent Th, four Fe, and two equivalent B atoms. There are two shorter (2.51 Å) and two longer (2.75 Å) Fe–Fe bond lengths. Both Fe–B bond lengths are 2.06 Å. In the fourth Fe site, Fe is bonded in a 2-coordinate geometry to two Th and twelve Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.63–2.79 Å. In the fifth Fe site, Fe is bonded in a distorted single-bond geometry to two Th, seven Fe, and one B atom. The Fe–Fe bond length is 2.60 Å. The Fe–B bond length is 2.10 Å. In the sixth Fe site, Fe is bonded to three Th and nine Fe atoms to form distorted FeTh3Fe9 cuboctahedra that share corners with eight FeTh4Fe8 cuboctahedra, an edgeedge with one FeTh3Fe9 cuboctahedra, and faces with four FeTh4Fe8 cuboctahedra. The Fe–Fe bond length is 2.41 Å. B is bonded in a 6-coordinate geometry to three Th and six Fe atoms.

36 MATERIALS SCIENCE↗
NASA NTRSDate not supplied

Capability Gaps Assessment and Identification of Critical Technology Elements for Mars Transit Habitat

The Habitation Systems Development Office (HP40) at NASA Marshall Space Flight Center supports systems engineering, integration, and project management for next generation space habitats. For in space operations and eventual transport of humans to Mars, NASA will rely on a Mars Transit Habitat (TH). The TH will be designed for an up to 1,200-day Mars mission and will carry all food and supplies needed to support four crew for this duration. In the current concept of operations, Mars TH transfers to near rectilinear halo orbit (NRHO) following launch and docks at Gateway as a visiting vehicle. While there, the TH will complete system shakedown testing and a series of analog missions which will grow from 3 to 6+ months in duration TH also augments Gateway’s habitation capabilities beyond 60-days. Proposed Gateway-TH missions will far exceed the longest duration cislunar human missions to date. These shakedown missions will also be the first operational readiness tests of Mars TH’s long-duration deep space systems, and of the split crew (two crew on the surface, two crew in space) operations that are vital to the approach for the first human Mars mission. Once shakedown missions are complete, Mars TH departs Gateway to aggregate with the Mars propulsion system in NRHO before onboarding the crew and final supplies in Earth orbit via a co-manifested Orion-logistics module. Orion and the LM return to Earth prior to the now aggregated Deep Space Transport vehicle’s journey to Mars. Development of the Mars TH requires significant technology development and maturation. Each year the agency performs a capability gaps assessment, where gaps developed by subject matter experts (SMEs) in various engineering/science disciplines are linked to architectural elements in formulation and prioritized. A gap captures the difference between the current state-of-the-art and the maturity of the capability that is needed to enable or enhance a mission as it is currently envisioned in the government reference architecture. HP40 conducted a gap analysis for Mars TH which will be summarized in this poster. Gaps classified as enabling (which means the mission cannot achieve success without gap closure) were subsequently used to identify critical technology elements (CTEs) for Mars TH. This identification of CTEs was also informed by an examination of the product breakdown structure for Mars TH and focused conversations with SMEs in specific technology areas. CTEs identified for Mars TH to date include the following (note this is not a comprehensive list – CTEs listed represent those in MSFC’s capability areas): inflatable softgoods for habitation; enhanced CO2 recovery; life support systems with greater levels of reliability and maintainability; autonomous guidance, navigation, command and control; and radiators for the Mars TH application. The habitation systems development team is currently delving deeper into each CTE to assess technology approaches being pursued, their maturity, and the degree of difficulty in maturation to meet projected Mars TH timelines. This poster will summarize work to date on the identification of enabling capability gaps linked to Mars TH and provide insight into the associated CTEs and technology maturation efforts.

technology development↗
DOE OSTI2020

Materials Data on Th6CBr14 by Materials Project

Th6CBr14 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. there are two inequivalent Th sites. In the first Th site, Th is bonded to one C and five Br atoms to form a mixture of distorted edge and corner-sharing ThCBr5 octahedra. The corner-sharing octahedra tilt angles range from 0–45°. The Th–C bond length is 2.56 Å. There are a spread of Th–Br bond distances ranging from 2.91–3.32 Å. In the second Th site, Th is bonded to one C and five Br atoms to form a mixture of edge and corner-sharing ThCBr5 octahedra. The corner-sharing octahedra tilt angles range from 0–45°. The Th–C bond length is 2.64 Å. There are a spread of Th–Br bond distances ranging from 2.90–3.04 Å. C is bonded in an octahedral geometry to six Th atoms. There are five inequivalent Br sites. In the first Br site, Br is bonded in an L-shaped geometry to two Th atoms. In the second Br site, Br is bonded in an L-shaped geometry to two Th atoms. In the third Br site, Br is bonded in a 3-coordinate geometry to three Th atoms. In the fourth Br site, Br is bonded in an L-shaped geometry to two equivalent Th atoms. In the fifth Br site, Br is bonded in a distorted bent 150 degrees geometry to two equivalent Th atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th2(FeCo)5 by Materials Project

Th2(FeCo)5 crystallizes in the orthorhombic Pmm2 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 twelve Fe and six Co atoms. There are a spread of Th–Fe bond distances ranging from 3.20–3.23 Å. There are four shorter (2.84 Å) and two longer (2.93 Å) Th–Co bond lengths. In the second Th site, Th is bonded in a 6-coordinate geometry to eight Fe and ten Co atoms. All Th–Fe bond lengths are 3.18 Å. There are a spread of Th–Co bond distances ranging from 2.88–3.23 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to four equivalent Th, four Fe, and four equivalent Co atoms to form distorted FeTh4Fe4Co4 cuboctahedra that share corners with four equivalent CoTh4Fe4Co4 cuboctahedra, corners with twelve FeTh4Fe4Co4 cuboctahedra, edges with ten FeTh4Fe4Co4 cuboctahedra, and faces with ten FeTh4Fe4Co4 cuboctahedra. There are two shorter (2.53 Å) and two longer (2.54 Å) Fe–Fe bond lengths. All Fe–Co bond lengths are 2.45 Å. In the second Fe site, Fe is bonded to four Th, three Fe, and five Co atoms to form distorted FeTh4Fe3Co5 cuboctahedra that share corners with two equivalent CoTh4Fe4Co4 cuboctahedra, corners with fourteen FeTh4Fe4Co4 cuboctahedra, edges with two equivalent CoTh4Fe4Co4 cuboctahedra, edges with eight FeTh4Fe4Co4 cuboctahedra, faces with two equivalent CoTh4Fe4Co4 cuboctahedra, and faces with eight FeTh4Fe4Co4 cuboctahedra. There are one shorter (2.50 Å) and one longer (2.52 Å) Fe–Fe bond lengths. There are a spread of Fe–Co bond distances ranging from 2.42–2.51 Å. In the third Fe site, Fe is bonded to four Th, three Fe, and five Co atoms to form distorted FeTh4Fe3Co5 cuboctahedra that share corners with two equivalent CoTh4Fe4Co4 cuboctahedra, corners with fourteen FeTh4Fe4Co4 cuboctahedra, edges with two equivalent CoTh4Fe4Co4 cuboctahedra, edges with eight FeTh4Fe4Co4 cuboctahedra, faces with two equivalent CoTh4Fe4Co4 cuboctahedra, and faces with eight FeTh4Fe4Co4 cuboctahedra. There are three shorter (2.45 Å) and two longer (2.46 Å) Fe–Co bond lengths. There are three inequivalent Co sites. In the first Co site, Co is bonded in a 12-coordinate geometry to three Th, four Fe, and two equivalent Co atoms. Both Co–Co bond lengths are 2.49 Å. In the second Co site, Co is bonded in a 12-coordinate geometry to three Th and six Fe atoms. In the third Co site, Co is bonded to four equivalent Th, four Fe, and four equivalent Co atoms to form distorted CoTh4Fe4Co4 cuboctahedra that share corners with four equivalent CoTh4Fe4Co4 cuboctahedra, corners with twelve FeTh4Fe4Co4 cuboctahedra, edges with two equivalent CoTh4Fe4Co4 cuboctahedra, edges with eight FeTh4Fe3Co5 cuboctahedra, faces with two equivalent CoTh4Fe4Co4 cuboctahedra, and faces with eight FeTh4Fe3Co5 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na7La7Th2Ti18O54 by Materials Project

Na7Th2La7Ti18O54 is Orthorhombic Perovskite-derived structured and crystallizes in the orthorhombic Fmm2 space group. The structure is three-dimensional. there are seven inequivalent Na sites. In the first Na site, Na is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of Na–O bond distances ranging from 2.47–2.80 Å. In the second Na site, Na is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of Na–O bond distances ranging from 2.55–3.02 Å. In the third Na site, Na is bonded in a 12-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.53–2.74 Å. In the fourth Na site, Na is bonded in a 12-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.54–2.74 Å. In the fifth Na site, Na is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of Na–O bond distances ranging from 2.53–2.98 Å. In the sixth Na site, Na is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of Na–O bond distances ranging from 2.51–2.89 Å. In the seventh Na site, Na is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.51–2.74 Å. There are two inequivalent Th sites. In the first Th site, Th is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of Th–O bond distances ranging from 2.39–2.74 Å. In the second Th site, Th is bonded in a 12-coordinate geometry to ten O atoms. There are a spread of Th–O bond distances ranging from 2.38–2.80 Å. There are seven inequivalent La sites. In the first La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.41–3.11 Å. In the second La site, La is bonded to twelve O atoms to form distorted LaO12 cuboctahedra that share corners with four equivalent LaO12 cuboctahedra and faces with eight TiO6 octahedra. There are a spread of La–O bond distances ranging from 2.47–3.04 Å. In the third La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.47–3.10 Å. In the fourth La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.47–3.07 Å. In the fifth La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.47–3.09 Å. In the sixth La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.48–3.07 Å. In the seventh La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.43–3.04 Å. There are ten inequivalent Ti sites. In the first Ti site, Ti is bonded to six O atoms to form TiO6 octahedra that share corners with six TiO6 octahedra and faces with two equivalent LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–19°. There are a spread of Ti–O bond distances ranging from 1.86–2.15 Å. In the second Ti site, Ti is bonded to six O atoms to form TiO6 octahedra that share corners with six TiO6 octahedra and faces with two equivalent LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–20°. There are a spread of Ti–O bond distances ranging from 1.96–1.99 Å. In the third Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–22°. There are a spread of Ti–O bond distances ranging from 1.94–2.01 Å. In the fourth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–22°. There are a spread of Ti–O bond distances ranging from 1.94–2.01 Å. In the fifth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–22°. There are a spread of Ti–O bond distances ranging from 1.94–2.01 Å. In the sixth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–19°. There are a spread of Ti–O bond distances ranging from 1.93–2.05 Å. In the seventh Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–23°. There are a spread of Ti–O bond distances ranging from 1.84–2.13 Å. In the eighth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–30°. There are a spread of Ti–O bond distances ranging from 1.90–2.00 Å. In the ninth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–25°. There are a spread of Ti–O bond distances ranging from 1.86–2.07 Å. In the tenth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–23°. There are a spread of Ti–O bond distances ranging from 1.84–2.13 Å. There are twenty-seven inequivalent O sites. In the first O site, O is bonded to two equivalent Na, two equivalent La, and two Ti atoms to form a mixture of distorted edge and corner-sharing ONa2La2Ti2 octahedra. The corner-sharing octahedra tilt angles range from 0–9°. In the second O site, O is bonded in a 5-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the third O site, O is bonded in a 3-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the fourth O site, O is bonded in a distorted linear geometry to two equivalent La and two Ti atoms. In the fifth O site, O is bonded in a 3-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the sixth O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the seventh O site, O is bonded in a distorted linear geometry to two equivalent Na, two equivalent La, and two Ti atoms. In the eighth O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the ninth O site, O is bonded in a 4-coordinate geometry to two Na, two La, and two equivalent Ti atoms. In the tenth O site, O is bonded to two equivalent Na, two equivalent La, and two Ti atoms to form a mixture of distorted edge and corner-sharing ONa2La2Ti2 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the eleventh O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the twelfth O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the thirteenth O site, O is bonded to two equivalent Na, two equivalent La, and two Ti atoms to form a mixture of distorted edge and corner-sharing ONa2La2Ti2 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the fourteenth O site, O is bonded in a 4-coordinate geometry to two Na, two La, and two equivalent Ti atoms. In the fifteenth O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the sixteenth O site, O is bonded in a distorted linear geometry to two equivalent Na, two equivalent La, and two Ti atoms. In the seventeenth O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the eighteenth O site, O is bonded in a 3-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the nineteenth O site, O is bonded in a distorted linear geometry to two equivalent La and two Ti atoms. In the twentieth O site, O is bonded in a 5-coordinate geometry to one Na, one Th, one La, and two equivalent Ti atoms. In the twenty-first O site, O is bonded in a 5-coordinate geometry to one Na, one Th, one La, and two equivalent Ti atoms. In the twenty-second O site, O is bonded in a 6-coordinate geometry to two equivalent Na, two equivalent Th, and two Ti atoms. In the twenty-third O site, O is bonded in a 4-coordinate geometry to one Na, one Th, and two equivalent Ti atoms. In the twenty-fourth O site, O is bonded in a 4-coordinate geometry to one Na, one Th, and two equivalent Ti atoms. In the twenty-fifth O site, O is bonded to two equivalent Na, two equivalent Th, and two Ti atoms to form distorted ONa2Th2Ti2 octahedra that share corners with five ONa2La2Ti2 octahedra and edges with four equivalent ONa2Th2Ti2 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the twenty-sixth O site, O is bonded in a 2-coordinate geometry to one Th, one La, and two equivalent Ti atoms. In the twenty-seventh O site, O is bonded in a 2-coordinate geometry to two Na, one Th, one La, and two equivalent Ti atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ThI3 by Materials Project

ThI3 crystallizes in the orthorhombic Cccm space group. The structure is three-dimensional. there are three inequivalent Th sites. In the first Th site, Th is bonded in a body-centered cubic geometry to eight I atoms. There are four shorter (3.29 Å) and four longer (3.33 Å) Th–I bond lengths. In the second Th site, Th is bonded in a 8-coordinate geometry to eight I atoms. There are four shorter (3.25 Å) and four longer (3.27 Å) Th–I bond lengths. In the third Th site, Th is bonded in a 8-coordinate geometry to eight I atoms. There are a spread of Th–I bond distances ranging from 3.19–3.34 Å. There are four inequivalent I sites. In the first I site, I is bonded in a 2-coordinate geometry to two equivalent Th atoms. In the second I site, I is bonded in a 2-coordinate geometry to two equivalent Th atoms. In the third I site, I is bonded in a distorted trigonal non-coplanar geometry to three Th atoms. In the fourth I site, I is bonded in a distorted trigonal non-coplanar geometry to three Th atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th7Te12 by Materials Project

Th7Te12 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. there are three inequivalent Th sites. In the first Th site, Th is bonded in a 8-coordinate geometry to eight Te atoms. There are a spread of Th–Te bond distances ranging from 3.17–3.37 Å. In the second Th site, Th is bonded in a 8-coordinate geometry to eight Te atoms. There are a spread of Th–Te bond distances ranging from 3.14–3.43 Å. In the third Th site, Th is bonded in a 9-coordinate geometry to nine Te atoms. There are three shorter (3.16 Å) and six longer (3.48 Å) Th–Te bond lengths. There are four inequivalent Te sites. In the first Te site, Te is bonded to four Th atoms to form TeTh4 tetrahedra that share corners with four equivalent TeTh4 tetrahedra, corners with nine TeTh5 trigonal bipyramids, and edges with eight TeTh5 trigonal bipyramids. In the second Te site, Te is bonded to five Th atoms to form distorted TeTh5 trigonal bipyramids that share corners with five equivalent TeTh4 tetrahedra, corners with ten TeTh5 trigonal bipyramids, edges with two equivalent TeTh4 tetrahedra, and edges with eight TeTh5 trigonal bipyramids. In the third Te site, Te is bonded to five Th atoms to form distorted TeTh5 trigonal bipyramids that share corners with two equivalent TeTh4 tetrahedra, corners with thirteen TeTh5 trigonal bipyramids, edges with two equivalent TeTh4 tetrahedra, and edges with eight TeTh5 trigonal bipyramids. In the fourth Te site, Te is bonded to five Th atoms to form distorted TeTh5 trigonal bipyramids that share corners with two equivalent TeTh4 tetrahedra, corners with eleven TeTh5 trigonal bipyramids, edges with four equivalent TeTh4 tetrahedra, and edges with eight TeTh5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on YThFe14B by Materials Project

ThYFe14B crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Th is bonded in a 1-coordinate geometry to one Th, two equivalent Y, sixteen Fe, and one B atom. The Th–Th bond length is 3.56 Å. Both Th–Y bond lengths are 3.80 Å. There are a spread of Th–Fe bond distances ranging from 3.05–3.37 Å. The Th–B bond length is 2.89 Å. Y is bonded in a 12-coordinate geometry to two equivalent Th, sixteen Fe, and two equivalent B atoms. There are a spread of Y–Fe bond distances ranging from 2.99–3.23 Å. Both Y–B bond lengths are 3.23 Å. There are six inequivalent Fe sites. In the first Fe site, Fe is bonded in a distorted single-bond geometry to one Th, one Y, seven Fe, and one B atom. There are a spread of Fe–Fe bond distances ranging from 2.46–2.72 Å. The Fe–B bond length is 2.09 Å. In the second Fe site, Fe is bonded in a 2-coordinate geometry to one Th, one Y, and twelve Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.61–2.77 Å. In the third Fe site, Fe is bonded to two equivalent Th, one Y, and nine Fe atoms to form a mixture of distorted corner, edge, and face-sharing FeYTh2Fe9 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.38–2.50 Å. In the fourth Fe site, Fe is bonded in a distorted q6 geometry to one Th, one Y, and ten Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.45–2.55 Å. In the fifth Fe site, Fe is bonded in a distorted L-shaped geometry to two equivalent Y, four Fe, and two equivalent B atoms. Both Fe–B bond lengths are 2.05 Å. In the sixth Fe site, Fe is bonded to two equivalent Th, two equivalent Y, and eight Fe atoms to form a mixture of corner and face-sharing FeY2Th2Fe8 cuboctahedra. B is bonded in a 6-coordinate geometry to one Th, two equivalent Y, and six Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th2(FeNi)5 by Materials Project

Th2(FeNi)5 crystallizes in the orthorhombic Pmmm 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 Fe and twelve Ni atoms. There are four shorter (2.91 Å) and two longer (2.92 Å) Th–Fe bond lengths. There are eight shorter (3.20 Å) and four longer (3.22 Å) Th–Ni bond lengths. In the second Th site, Th is bonded in a 6-coordinate geometry to ten Fe and eight equivalent Ni atoms. There are a spread of Th–Fe bond distances ranging from 2.87–3.22 Å. All Th–Ni bond lengths are 3.20 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded in a 12-coordinate geometry to three Th, two equivalent Fe, and four equivalent Ni atoms. Both Fe–Fe bond lengths are 2.44 Å. All Fe–Ni bond lengths are 2.49 Å. In the second Fe site, Fe is bonded in a 12-coordinate geometry to three Th and six Ni atoms. There are four shorter (2.46 Å) and two longer (2.47 Å) Fe–Ni bond lengths. In the third Fe site, Fe is bonded to four equivalent Th, four equivalent Fe, and four equivalent Ni atoms to form distorted FeTh4Fe4Ni4 cuboctahedra that share corners with four equivalent FeTh4Fe4Ni4 cuboctahedra, corners with twelve NiTh4Fe5Ni3 cuboctahedra, edges with two equivalent FeTh4Fe4Ni4 cuboctahedra, edges with eight equivalent NiTh4Fe5Ni3 cuboctahedra, faces with two equivalent FeTh4Fe4Ni4 cuboctahedra, and faces with eight equivalent NiTh4Fe5Ni3 cuboctahedra. All Fe–Ni bond lengths are 2.51 Å. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded to four equivalent Th, four equivalent Fe, and four equivalent Ni atoms to form distorted NiTh4Fe4Ni4 cuboctahedra that share corners with four equivalent FeTh4Fe4Ni4 cuboctahedra, corners with twelve NiTh4Fe5Ni3 cuboctahedra, edges with ten NiTh4Fe5Ni3 cuboctahedra, and faces with ten NiTh4Fe4Ni4 cuboctahedra. All Ni–Ni bond lengths are 2.49 Å. In the second Ni site, Ni is bonded to four Th, five Fe, and three Ni atoms to form distorted NiTh4Fe5Ni3 cuboctahedra that share corners with two equivalent FeTh4Fe4Ni4 cuboctahedra, corners with fourteen NiTh4Fe4Ni4 cuboctahedra, edges with two equivalent FeTh4Fe4Ni4 cuboctahedra, edges with eight NiTh4Fe4Ni4 cuboctahedra, faces with two equivalent FeTh4Fe4Ni4 cuboctahedra, and faces with eight NiTh4Fe4Ni4 cuboctahedra. There are one shorter (2.50 Å) and one longer (2.54 Å) Ni–Ni bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KThN5O17 by Materials Project

KThN5O17 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of K–O bond distances ranging from 2.86–3.32 Å. Th is bonded in a distorted cuboctahedral geometry to twelve O atoms. There are a spread of Th–O bond distances ranging from 2.35–2.68 Å. There are five 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 1.24–1.29 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 1.23–1.29 Å. In the third 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 fourth 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. In the fifth 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 seventeen 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 distorted single-bond geometry to one K, one Th, and 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 two equivalent K and one N atom. In the fifth O site, O is bonded in a distorted single-bond geometry to one K, one Th, and one N atom. In the sixth O site, O is bonded in a single-bond geometry to one Th atom. In the seventh O site, O is bonded in a distorted single-bond geometry to one K and one N atom. In the eighth O site, O is bonded in a distorted single-bond geometry to one K, one Th, and one N atom. In the ninth O site, O is bonded in a distorted single-bond geometry to one K and one N atom. In the tenth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the eleventh O site, O is bonded in a single-bond geometry to one Th and one N atom. In the twelfth O site, O is bonded in a single-bond geometry to one K and one Th atom. In the thirteenth O site, O is bonded in a distorted water-like geometry to one Th and one N atom. In the fourteenth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the fifteenth O site, O is bonded in a single-bond geometry to one Th and one N atom. In the sixteenth O site, O is bonded in a distorted single-bond geometry to one K and one N atom. In the seventeenth O site, O is bonded in a single-bond geometry to one K and one N atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on DyThFe14B by Materials Project

ThDyFe14B crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Th is bonded in a 1-coordinate geometry to one Th, two equivalent Dy, sixteen Fe, and one B atom. The Th–Th bond length is 3.57 Å. Both Th–Dy bond lengths are 3.79 Å. There are a spread of Th–Fe bond distances ranging from 3.05–3.36 Å. The Th–B bond length is 2.88 Å. Dy is bonded in a 10-coordinate geometry to two equivalent Th, sixteen Fe, and two equivalent B atoms. There are a spread of Dy–Fe bond distances ranging from 2.98–3.23 Å. Both Dy–B bond lengths are 3.22 Å. There are six inequivalent Fe sites. In the first Fe site, Fe is bonded in a distorted L-shaped geometry to two equivalent Dy, four Fe, and two equivalent B atoms. There are two shorter (2.50 Å) and two longer (2.75 Å) Fe–Fe bond lengths. Both Fe–B bond lengths are 2.05 Å. In the second Fe site, Fe is bonded in a distorted q6 geometry to one Th, one Dy, and ten Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.37–2.65 Å. In the third Fe site, Fe is bonded in a 2-coordinate geometry to one Th, one Dy, and twelve Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.65–2.75 Å. In the fourth Fe site, Fe is bonded in a distorted single-bond geometry to one Th, one Dy, seven Fe, and one B atom. There are one shorter (2.55 Å) and one longer (2.58 Å) Fe–Fe bond lengths. The Fe–B bond length is 2.08 Å. In the fifth Fe site, Fe is bonded to two equivalent Th, two equivalent Dy, and eight Fe atoms to form FeDy2Th2Fe8 cuboctahedra that share corners with twelve FeDy2Th2Fe8 cuboctahedra and faces with four equivalent FeDyTh2Fe9 cuboctahedra. In the sixth Fe site, Fe is bonded to two equivalent Th, one Dy, and nine Fe atoms to form distorted FeDyTh2Fe9 cuboctahedra that share corners with eight FeDy2Th2Fe8 cuboctahedra, an edgeedge with one FeDyTh2Fe9 cuboctahedra, and faces with four FeDy2Th2Fe8 cuboctahedra. The Fe–Fe bond length is 2.42 Å. B is bonded in a 6-coordinate geometry to one Th, two equivalent Dy, and six Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th7S12 by Materials Project

Th7S12 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. there are three inequivalent Th sites. In the first Th site, Th is bonded in a 9-coordinate geometry to nine S atoms. There are three shorter (2.79 Å) and six longer (3.08 Å) Th–S bond lengths. In the second Th site, Th is bonded in a 8-coordinate geometry to eight S atoms. There are a spread of Th–S bond distances ranging from 2.81–3.01 Å. In the third Th site, Th is bonded in a 8-coordinate geometry to eight S atoms. There are a spread of Th–S bond distances ranging from 2.76–3.01 Å. There are four inequivalent S sites. In the first S site, S is bonded to five Th atoms to form distorted STh5 trigonal bipyramids that share corners with five equivalent STh4 tetrahedra, corners with ten STh5 trigonal bipyramids, edges with two equivalent STh4 tetrahedra, and edges with eight STh5 trigonal bipyramids. In the second S site, S is bonded to five Th atoms to form distorted STh5 trigonal bipyramids that share corners with two equivalent STh4 tetrahedra, corners with thirteen STh5 trigonal bipyramids, edges with two equivalent STh4 tetrahedra, and edges with eight STh5 trigonal bipyramids. In the third S site, S is bonded to four Th atoms to form STh4 tetrahedra that share corners with four equivalent STh4 tetrahedra, corners with nine STh5 trigonal bipyramids, and edges with eight STh5 trigonal bipyramids. In the fourth S site, S is bonded to five Th atoms to form distorted STh5 trigonal bipyramids that share corners with two equivalent STh4 tetrahedra, corners with eleven STh5 trigonal bipyramids, edges with four equivalent STh4 tetrahedra, and edges with eight STh5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2021

The solubility of thorium in carbonate-bearing solutions at hydrothermal conditions

Thorium mineralization is frequently hosted in carbonate-bearing rocks, and thorium commonly substitutes into the structures of carbonate-bearing minerals that have precipitated from or been modified by hydrothermal fluids. Given this common association, it is reasonable to consider the hypothesis that the presence of carbonate ligands in hydrothermal solutions promotes the transport of Th through the formation of stable aqueous complexes. Our ability to evaluate this hypothesis, however, is hindered by the lack of experimental data for Th-carbonate species at conditions beyond ambient. The low-temperature data indicate that carbonate is a strong complexing agent for Th. In this contribution, we investigate the solubility of Th in carbonate-bearing fluids relevant to natural systems (0.05–0.5 m NaHCO 3 /Na 2 CO 3 ; pH T ~ 7.8–9.8) at elevated temperature (175–250 °C). We demonstrate that, in contrast to the behavior of Th at low temperature, the stability of Th-carbonate complexes is not sufficient for them to predominate at these conditions. Instead, the solubility of Th is governed by hydrolysis reactions. Under the experimental conditions investigated, the predominant hydroxyl complexes are Th(OH) 4 0 and Th(OH) 5 -. Furthermore, thermodynamic formation constants were derived for these species at the temperatures considered in our experiments (log β 4 = 43.34 and 44.31 at 175 and 200 °C, respectively, and log β 5 = 46.15 and 47.9 at 225 and 250 °C, respectively) to permit forward modeling of Th mobility in natural systems. Our study indicates that carbonate ions are unlikely to play a role in transporting Th in hydrothermal fluids. Summarizing the results of this study and our previous studies of the solubility of Th in hydrothermal fluids, we conclude that SO 4 2- is the primary ligand responsible for the hydrothermal transport of Th.

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

Materials Data on Th3Si2 by Materials Project

Th3Si2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. there are two inequivalent Th sites. In the first Th site, Th is bonded in a 1-coordinate geometry to four equivalent Th and three equivalent Si atoms. All Th–Th bond lengths are 3.78 Å. There are one shorter (2.77 Å) and two longer (2.97 Å) Th–Si bond lengths. In the second Th site, Th is bonded in a distorted q6 geometry to ten Th atoms. Both Th–Th bond lengths are 3.41 Å. Si is bonded in a 4-coordinate geometry to three equivalent Th and one Si atom. The Si–Si bond length is 2.26 Å.

36 MATERIALS SCIENCE↗