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DOE OSTI2020

Materials Data on CaCr4O8 by Materials Project

CaCr4O8 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Ca2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ca–O bond distances ranging from 2.36–2.62 Å. There are four inequivalent Cr+3.50+ sites. In the first Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing CrO6 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Cr–O bond distances ranging from 1.97–2.08 Å. In the second Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing CrO6 octahedra. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Cr–O bond distances ranging from 1.85–2.11 Å. In the third Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing CrO6 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Cr–O bond distances ranging from 1.84–2.00 Å. In the fourth Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing CrO6 octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Cr–O bond distances ranging from 1.95–2.08 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three Cr+3.50+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Cr+3.50+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to three Cr+3.50+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Cr+3.50+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Cr+3.50+ atoms. In the sixth O2- site, O2- is bonded to two equivalent Ca2+ and three Cr+3.50+ atoms to form a mixture of distorted edge and corner-sharing OCa2Cr3 trigonal bipyramids. In the seventh O2- site, O2- is bonded to two equivalent Ca2+ and three Cr+3.50+ atoms to form a mixture of distorted edge and corner-sharing OCa2Cr3 trigonal bipyramids. In the eighth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Cr+3.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ZnCr4O8 by Materials Project

Cr4ZnO8 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Cr+3.50+ sites. In the first Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four CrO6 octahedra, edges with four CrO6 octahedra, and edges with two equivalent ZnO5 square pyramids. The corner-sharing octahedra tilt angles range from 48–52°. There are a spread of Cr–O bond distances ranging from 1.92–2.15 Å. In the second Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form distorted CrO6 octahedra that share corners with four CrO6 octahedra, corners with two equivalent ZnO5 square pyramids, edges with four CrO6 octahedra, and a faceface with one ZnO5 square pyramid. The corner-sharing octahedra tilt angles range from 48–55°. There are a spread of Cr–O bond distances ranging from 1.89–2.19 Å. In the third Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four CrO6 octahedra, corners with two equivalent ZnO5 square pyramids, and edges with four CrO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of Cr–O bond distances ranging from 1.92–2.06 Å. In the fourth Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four CrO6 octahedra, corners with two equivalent ZnO5 square pyramids, edges with four CrO6 octahedra, and an edgeedge with one ZnO5 square pyramid. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Cr–O bond distances ranging from 1.92–2.12 Å. Zn2+ is bonded to five O2- atoms to form ZnO5 square pyramids that share corners with six CrO6 octahedra, edges with three CrO6 octahedra, edges with two equivalent ZnO5 square pyramids, and a faceface with one CrO6 octahedra. The corner-sharing octahedra tilt angles range from 6–56°. There are a spread of Zn–O bond distances ranging from 2.09–2.16 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three Cr+3.50+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Cr+3.50+ atoms. In the third O2- site, O2- is bonded in a trigonal planar geometry to three Cr+3.50+ atoms. In the fourth O2- site, O2- is bonded to three Cr+3.50+ and one Zn2+ atom to form OZnCr3 trigonal pyramids that share corners with two equivalent OZnCr3 trigonal pyramids, edges with two equivalent OZn2Cr3 square pyramids, and edges with two equivalent OZn2Cr3 trigonal bipyramids. In the fifth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Cr+3.50+ atoms. In the sixth O2- site, O2- is bonded to three Cr+3.50+ and two equivalent Zn2+ atoms to form distorted OZn2Cr3 trigonal bipyramids that share corners with two equivalent OZn2Cr3 square pyramids, an edgeedge with one OZn2Cr3 square pyramid, edges with two equivalent OZn2Cr3 trigonal bipyramids, and edges with two equivalent OZnCr3 trigonal pyramids. In the seventh O2- site, O2- is bonded to three Cr+3.50+ and two equivalent Zn2+ atoms to form OZn2Cr3 square pyramids that share corners with two equivalent OZn2Cr3 trigonal bipyramids, edges with two equivalent OZn2Cr3 square pyramids, an edgeedge with one OZn2Cr3 trigonal bipyramid, and edges with two equivalent OZnCr3 trigonal pyramids. In the eighth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Cr+3.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ta3Cr5N4 by Materials Project

(CrTaN)2TaCr3N2 crystallizes in the tetragonal P4mm space group. The structure is two-dimensional and consists of one CrTaN sheet oriented in the (0, 0, 1) direction and one TaCr3N2 sheet oriented in the (0, 0, 1) direction. In the CrTaN sheet, there are two inequivalent Ta sites. In the first Ta site, Ta is bonded to five N atoms to form a mixture of distorted corner and edge-sharing TaN5 square pyramids. There are four shorter (2.14 Å) and one longer (2.30 Å) Ta–N bond lengths. In the second Ta site, Ta is bonded to five N atoms to form a mixture of distorted corner and edge-sharing TaN5 square pyramids. There are four shorter (2.14 Å) and one longer (2.32 Å) Ta–N bond lengths. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a single-bond geometry to one N atom. The Cr–N bond length is 2.10 Å. In the second Cr site, Cr is bonded in a single-bond geometry to one N atom. The Cr–N bond length is 2.08 Å. There are two inequivalent N sites. In the first N site, N is bonded to five Ta and one Cr atom to form a mixture of corner and edge-sharing NTa5Cr octahedra. The corner-sharing octahedral tilt angles are 19°. In the second N site, N is bonded to five Ta and one Cr atom to form a mixture of corner and edge-sharing NTa5Cr octahedra. The corner-sharing octahedral tilt angles are 18°. In the TaCr3N2 sheet, Ta is bonded to five N atoms to form TaN5 square pyramids that share corners with four equivalent TaN5 square pyramids, edges with four equivalent TaN5 square pyramids, and edges with four equivalent CrN5 square pyramids. There are four shorter (2.13 Å) and one longer (2.23 Å) Ta–N bond lengths. There are three inequivalent Cr sites. In the first Cr site, Cr is bonded in a single-bond geometry to one N atom. The Cr–N bond length is 2.06 Å. In the second Cr site, Cr is bonded in a single-bond geometry to one N atom. The Cr–N bond length is 1.87 Å. In the third Cr site, Cr is bonded to five N atoms to form CrN5 square pyramids that share corners with four equivalent CrN5 square pyramids, edges with four equivalent TaN5 square pyramids, and edges with four equivalent CrN5 square pyramids. There are four shorter (2.12 Å) and one longer (2.17 Å) Cr–N bond lengths. There are two inequivalent N sites. In the first N site, N is bonded to four equivalent Ta and two Cr atoms to form a mixture of corner and edge-sharing NTa4Cr2 octahedra. The corner-sharing octahedral tilt angles are 15°. In the second N site, N is bonded to one Ta and five Cr atoms to form NTaCr5 octahedra that share corners with four equivalent NTaCr5 octahedra and edges with eight NTa4Cr2 octahedra. The corner-sharing octahedral tilt angles are 12°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CrPd by Materials Project

PdCr crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Cr sites. In the first Cr site, Cr is bonded to six equivalent Cr and six equivalent Pd atoms to form distorted CrCr6Pd6 cuboctahedra that share corners with twelve CrCr6Pd6 cuboctahedra, edges with twelve CrCr6Pd6 cuboctahedra, edges with twelve equivalent PdCr6Pd6 cuboctahedra, faces with six equivalent CrCr6Pd6 cuboctahedra, and faces with twelve equivalent PdCr6Pd6 cuboctahedra. All Cr–Cr bond lengths are 2.68 Å. All Cr–Pd bond lengths are 2.68 Å. In the second Cr site, Cr is bonded to six equivalent Cr and six Pd atoms to form distorted CrCr6Pd6 cuboctahedra that share corners with five equivalent PdCr6Pd10 cuboctahedra, corners with twelve CrCr6Pd6 cuboctahedra, edges with ten PdCr6Pd6 cuboctahedra, edges with twelve CrCr6Pd6 cuboctahedra, faces with six equivalent CrCr6Pd6 cuboctahedra, and faces with fifteen PdCr6Pd6 cuboctahedra. All Cr–Cr bond lengths are 2.68 Å. All Cr–Pd bond lengths are 2.68 Å. In the third Cr site, Cr is bonded to six equivalent Cr and six Pd atoms to form distorted CrCr6Pd6 cuboctahedra that share corners with five equivalent PdCr6Pd10 cuboctahedra, corners with twelve CrCr6Pd6 cuboctahedra, edges with ten PdCr6Pd6 cuboctahedra, edges with twelve CrCr6Pd6 cuboctahedra, faces with six equivalent CrCr6Pd6 cuboctahedra, and faces with fifteen PdCr6Pd6 cuboctahedra. All Cr–Cr bond lengths are 2.68 Å. All Cr–Pd bond lengths are 2.68 Å. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded to six Cr and six equivalent Pd atoms to form distorted PdCr6Pd6 cuboctahedra that share corners with twelve PdCr6Pd6 cuboctahedra, edges with twelve CrCr6Pd6 cuboctahedra, edges with twelve PdCr6Pd6 cuboctahedra, faces with six equivalent PdCr6Pd6 cuboctahedra, and faces with twelve CrCr6Pd6 cuboctahedra. All Pd–Pd bond lengths are 2.68 Å. In the second Pd site, Pd is bonded to six Cr and ten equivalent Pd atoms to form distorted PdCr6Pd10 cuboctahedra that share corners with ten CrCr6Pd6 cuboctahedra, corners with twelve PdCr6Pd6 cuboctahedra, edges with eight CrCr6Pd6 cuboctahedra, edges with sixteen PdCr6Pd6 cuboctahedra, faces with sixteen equivalent PdCr6Pd10 cuboctahedra, and faces with eighteen CrCr6Pd6 cuboctahedra. There are a spread of Pd–Pd bond distances ranging from 2.68–5.36 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NbAlCr4 by Materials Project

NbCr4Al is Hexagonal Laves-derived structured and crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Nb is bonded in a 12-coordinate geometry to three equivalent Nb, twelve Cr, and one Al atom. All Nb–Nb bond lengths are 2.99 Å. There are a spread of Nb–Cr bond distances ranging from 2.84–2.88 Å. The Nb–Al bond length is 2.91 Å. There are three inequivalent Cr sites. In the first Cr site, Cr is bonded to six equivalent Cr and six equivalent Al atoms to form CrAl6Cr6 cuboctahedra that share corners with twelve equivalent CrNb3Al3Cr6 cuboctahedra, edges with six equivalent CrAl6Cr6 cuboctahedra, and faces with twenty CrNb6Cr6 cuboctahedra. All Cr–Cr bond lengths are 2.40 Å. All Cr–Al bond lengths are 2.87 Å. In the second Cr site, Cr is bonded to six equivalent Nb and six equivalent Cr atoms to form CrNb6Cr6 cuboctahedra that share corners with twelve equivalent CrNb3Al3Cr6 cuboctahedra, edges with six equivalent CrNb6Cr6 cuboctahedra, and faces with twenty CrAl6Cr6 cuboctahedra. All Cr–Cr bond lengths are 2.47 Å. In the third Cr site, Cr is bonded to three equivalent Nb, six Cr, and three equivalent Al atoms to form CrNb3Al3Cr6 cuboctahedra that share corners with eighteen CrAl6Cr6 cuboctahedra, edges with six equivalent CrNb3Al3Cr6 cuboctahedra, and faces with eighteen CrAl6Cr6 cuboctahedra. There are two shorter (2.39 Å) and two longer (2.51 Å) Cr–Cr bond lengths. There are one shorter (2.77 Å) and two longer (2.83 Å) Cr–Al bond lengths. Al is bonded in a 9-coordinate geometry to one Nb, twelve Cr, and three equivalent Al atoms. All Al–Al bond lengths are 3.00 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaCr4Si by Materials Project

TaCr4Si crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Ta is bonded in a 1-coordinate geometry to three equivalent Ta, twelve Cr, and one Si atom. All Ta–Ta bond lengths are 2.99 Å. There are three shorter (2.85 Å) and nine longer (2.86 Å) Ta–Cr bond lengths. The Ta–Si bond length is 2.79 Å. There are three inequivalent Cr sites. In the first Cr site, Cr is bonded to six equivalent Cr and six equivalent Si atoms to form CrCr6Si6 cuboctahedra that share corners with twelve equivalent CrTa3Cr6Si3 cuboctahedra, edges with six equivalent CrCr6Si6 cuboctahedra, and faces with twenty CrTa6Cr6 cuboctahedra. All Cr–Cr bond lengths are 2.33 Å. All Cr–Si bond lengths are 2.86 Å. In the second Cr site, Cr is bonded to six equivalent Ta and six equivalent Cr atoms to form CrTa6Cr6 cuboctahedra that share corners with twelve equivalent CrTa3Cr6Si3 cuboctahedra, edges with six equivalent CrTa6Cr6 cuboctahedra, and faces with twenty CrCr6Si6 cuboctahedra. All Cr–Cr bond lengths are 2.47 Å. In the third Cr site, Cr is bonded to three equivalent Ta, six Cr, and three equivalent Si atoms to form CrTa3Cr6Si3 cuboctahedra that share corners with eighteen CrCr6Si6 cuboctahedra, edges with six equivalent CrTa3Cr6Si3 cuboctahedra, and faces with eighteen CrCr6Si6 cuboctahedra. There are two shorter (2.36 Å) and two longer (2.51 Å) Cr–Cr bond lengths. There are one shorter (2.71 Å) and two longer (2.76 Å) Cr–Si bond lengths. Si is bonded in a 10-coordinate geometry to one Ta and twelve Cr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr3Fe2O15 by Materials Project

Cr2FeO8CrFeO7 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of two CrFeO7 ribbons oriented in the (0, 1, 0) direction and one Cr2FeO8 sheet oriented in the (0, 0, 1) direction. In each CrFeO7 ribbon, Cr is bonded to four O atoms to form CrO4 tetrahedra that share corners with two equivalent FeO5 trigonal bipyramids. There are a spread of Cr–O bond distances ranging from 1.60–1.80 Å. Fe is bonded to five O atoms to form FeO5 trigonal bipyramids that share corners with two equivalent CrO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.65–1.90 Å. There are seven inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Fe atom. In the second O site, O is bonded in a single-bond geometry to one Fe atom. In the third O site, O is bonded in a single-bond geometry to one Fe atom. In the fourth O site, O is bonded in a single-bond geometry to one Cr atom. In the fifth O site, O is bonded in a bent 150 degrees geometry to one Cr and one Fe atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Cr and one Fe atom. In the seventh O site, O is bonded in a single-bond geometry to one Cr atom. In the Cr2FeO8 sheet, there are two inequivalent Cr sites. In the first Cr site, Cr is bonded to four O atoms to form CrO4 tetrahedra that share corners with three equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 24–59°. There are a spread of Cr–O bond distances ranging from 1.61–1.77 Å. In the second Cr site, Cr is bonded to four O atoms to form CrO4 tetrahedra that share corners with three equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 11–33°. There are a spread of Cr–O bond distances ranging from 1.60–1.71 Å. Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six CrO4 tetrahedra and an edgeedge with one FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.98–2.10 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a distorted trigonal planar geometry to one Cr and two equivalent Fe atoms. In the second O site, O is bonded in a linear geometry to one Cr and one Fe atom. In the third O site, O is bonded in a single-bond geometry to one Cr atom. In the fourth O site, O is bonded in a single-bond geometry to one Cr atom. In the fifth O site, O is bonded in a single-bond geometry to one Cr atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Cr and one Fe atom. In the seventh O site, O is bonded in a bent 150 degrees geometry to one Cr and one Fe atom. In the eighth O site, O is bonded in a bent 150 degrees geometry to one Cr and one Fe atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr5NiSn12 by Materials Project

NiCr5Sn12 is Khatyrkite-derived structured and crystallizes in the orthorhombic C222 space group. The structure is three-dimensional. there are three inequivalent Cr sites. In the first Cr site, Cr is bonded in a 10-coordinate geometry to two equivalent Cr and eight Sn atoms. Both Cr–Cr bond lengths are 2.76 Å. There are a spread of Cr–Sn bond distances ranging from 2.77–2.88 Å. In the second Cr site, Cr is bonded in a 10-coordinate geometry to two equivalent Cr and eight Sn atoms. There are a spread of Cr–Sn bond distances ranging from 2.79–2.87 Å. In the third Cr site, Cr is bonded in a distorted q6 geometry to two equivalent Ni and eight Sn atoms. Both Cr–Ni bond lengths are 2.77 Å. There are four shorter (2.75 Å) and four longer (2.86 Å) Cr–Sn bond lengths. Ni is bonded in a distorted q6 geometry to two equivalent Cr and eight Sn atoms. There are four shorter (2.75 Å) and four longer (2.86 Å) Ni–Sn bond lengths. There are five inequivalent Sn sites. In the first Sn site, Sn is bonded in a 4-coordinate geometry to three Cr and one Ni atom. In the second Sn site, Sn is bonded in a 4-coordinate geometry to four Cr atoms. In the third Sn site, Sn is bonded in a 2-coordinate geometry to two equivalent Cr, two equivalent Ni, and three Sn atoms. There are one shorter (3.04 Å) and two longer (3.14 Å) Sn–Sn bond lengths. In the fourth Sn site, Sn is bonded in a 4-coordinate geometry to four Cr and one Sn atom. In the fifth Sn site, Sn is bonded in a 4-coordinate geometry to four Cr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr3(P2O7)2 by Materials Project

Cr3(P2O7)2 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one Cr3(P2O7)2 sheet oriented in the (0, 0, 1) direction. there are three inequivalent Cr+2.67+ sites. In the first Cr+2.67+ site, Cr+2.67+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.93–2.23 Å. In the second Cr+2.67+ site, Cr+2.67+ is bonded to five O2- atoms to form CrO5 trigonal bipyramids that share corners with five PO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 2.02–2.24 Å. In the third Cr+2.67+ site, Cr+2.67+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Cr–O bond distances ranging from 2.03–2.62 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CrO6 octahedra, a cornercorner with one PO4 tetrahedra, and a cornercorner with one CrO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 38–50°. There are a spread of P–O bond distances ranging from 1.51–1.57 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CrO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–42°. There are a spread of P–O bond distances ranging from 1.50–1.66 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one PO4 tetrahedra and corners with three equivalent CrO5 trigonal bipyramids. There are a spread of P–O bond distances ranging from 1.52–1.63 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CrO6 octahedra, a cornercorner with one PO4 tetrahedra, and a cornercorner with one CrO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 23–46°. There are a spread of P–O bond distances ranging from 1.49–1.62 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Cr+2.67+ and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two Cr+2.67+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+2.67+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+2.67+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+2.67+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+2.67+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+2.67+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr+2.67+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+2.67+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+2.67+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+2.67+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NbCr4Si by Materials Project

NbCr4Si crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Nb is bonded in a 1-coordinate geometry to three equivalent Nb, twelve Cr, and one Si atom. All Nb–Nb bond lengths are 3.00 Å. There are six shorter (2.85 Å) and six longer (2.86 Å) Nb–Cr bond lengths. The Nb–Si bond length is 2.79 Å. There are three inequivalent Cr sites. In the first Cr site, Cr is bonded to six equivalent Nb and six equivalent Cr atoms to form CrNb6Cr6 cuboctahedra that share corners with twelve equivalent CrNb3Cr6Si3 cuboctahedra, edges with six equivalent CrNb6Cr6 cuboctahedra, and faces with twenty CrCr6Si6 cuboctahedra. All Cr–Cr bond lengths are 2.47 Å. In the second Cr site, Cr is bonded to six equivalent Cr and six equivalent Si atoms to form CrCr6Si6 cuboctahedra that share corners with twelve equivalent CrNb3Cr6Si3 cuboctahedra, edges with six equivalent CrCr6Si6 cuboctahedra, and faces with twenty CrNb6Cr6 cuboctahedra. All Cr–Cr bond lengths are 2.33 Å. All Cr–Si bond lengths are 2.86 Å. In the third Cr site, Cr is bonded to three equivalent Nb, six Cr, and three equivalent Si atoms to form CrNb3Cr6Si3 cuboctahedra that share corners with eighteen CrNb6Cr6 cuboctahedra, edges with six equivalent CrNb3Cr6Si3 cuboctahedra, and faces with eighteen CrNb6Cr6 cuboctahedra. There are two shorter (2.37 Å) and two longer (2.51 Å) Cr–Cr bond lengths. There are one shorter (2.71 Å) and two longer (2.76 Å) Cr–Si bond lengths. Si is bonded in a 10-coordinate geometry to one Nb and twelve Cr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Vadose Zone Soil Flushing for Chromium Remediation: A Laboratory Investigation to Support Field‐scale Application

Cr(VI) flushing from the vadose zone to the groundwater (with subsequent Cr(VI) removal in groundwater by pump-and-treat system) is a promising remedial technique that has recently been used at field scale. This laboratory study was conducted to provide the technical basis to design a field soil flushing strategy. The objectives were to (1) quantify the relationship between sediment Cr(VI) and Cr(III) mass and release rates and subsequent Cr(VI) leaching; (2) investigate different methodologies to maximize Cr(VI) leaching, and (3) investigate methods to minimize leaching of remaining residual Cr. Characterization of Cr-contaminated sediments (Hanford Site, WA) exhibited Cr(VI) showed that leach rates that were correlated to different Cr surface phases. Sediments with low leachable Cr(VI) (<2 μg/g) leached Cr rapidly, so slow infiltration of water in a single pulse was sufficient to leach most Cr. In contrast, sediments with high Cr (2 to 200 μg/g) released some Cr(VI) quickly but 10 to 50% Cr(VI) slowly (tens to hundreds of hours). Efficient unsaturated leaching of these sediments required a different infiltration strategy that includes: multiple slow leach pulses with time between flushing cycles; the use of a surfactant to increase Cr leaching from low-permeability zones, and the use of a reductant (Na-dithionite or Ca-polysulfide) in the final leach water was highly effective at decreasing residual Cr leaching. This study clearly demonstrated that the methodology of basing laboratory Cr flushing on parameters such as Cr release mass and rates could be used to improve the efficiency of soil flushing at field scale.

Accelerated Cr Flushing↗
DOE OSTI2020

Materials Data on Cr3GeN by Materials Project

GeNCr3 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Cr sites. In the first Cr site, Cr is bonded in a distorted bent 150 degrees geometry to three Ge and two equivalent N atoms. There are a spread of Cr–Ge bond distances ranging from 2.47–2.65 Å. There is one shorter (1.93 Å) and one longer (1.94 Å) Cr–N bond length. In the second Cr site, Cr is bonded in a linear geometry to four Ge and two equivalent N atoms. There are three shorter (2.67 Å) and one longer (2.68 Å) Cr–Ge bond lengths. There are one shorter (2.00 Å) and one longer (2.01 Å) Cr–N bond lengths. In the third Cr site, Cr is bonded in a distorted bent 150 degrees geometry to three Ge and two equivalent N atoms. There are a spread of Cr–Ge bond distances ranging from 2.48–2.65 Å. Both Cr–N bond lengths are 1.94 Å. In the fourth Cr site, Cr is bonded in a distorted bent 150 degrees geometry to three Ge and two equivalent N atoms. There are a spread of Cr–Ge bond distances ranging from 2.48–2.64 Å. Both Cr–N bond lengths are 1.94 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a distorted q6 geometry to ten Cr atoms. In the second Ge site, Ge is bonded in a distorted q6 geometry to ten Cr atoms. N is bonded to six Cr atoms to form corner-sharing NCr6 octahedra. The corner-sharing octahedra tilt angles range from 0–27°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr23C6 by Materials Project

Cr23C6 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are four inequivalent Cr sites. In the first Cr site, Cr is bonded in a cuboctahedral geometry to twelve equivalent Cr atoms. All Cr–Cr bond lengths are 2.53 Å. In the second Cr site, Cr is bonded in a distorted tetrahedral geometry to four equivalent Cr atoms. All Cr–Cr bond lengths are 2.40 Å. In the third Cr site, Cr is bonded in a distorted trigonal non-coplanar geometry to one Cr and three equivalent C atoms. All Cr–C bond lengths are 2.09 Å. In the fourth Cr site, Cr is bonded in a bent 150 degrees geometry to one Cr and two equivalent C atoms. Both Cr–C bond lengths are 2.12 Å. C is bonded in a 8-coordinate geometry to eight Cr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MnCr3(PO4)4 by Materials Project

Cr3Mn(PO4)4 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are three inequivalent Cr+3.33+ sites. In the first Cr+3.33+ site, Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Cr–O bond distances ranging from 1.96–2.10 Å. In the second Cr+3.33+ site, Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent MnO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Cr–O bond distances ranging from 1.98–2.08 Å. In the third Cr+3.33+ site, Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Cr–O bond distances ranging from 1.96–2.09 Å. Mn2+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Mn–O bond distances ranging from 1.90–2.26 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two CrO6 octahedra, corners with two equivalent MnO6 octahedra, and an edgeedge with one CrO6 octahedra. The corner-sharing octahedra tilt angles range from 44–56°. There is two shorter (1.52 Å) and two longer (1.59 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four CrO6 octahedra and an edgeedge with one CrO6 octahedra. The corner-sharing octahedra tilt angles range from 46–57°. There are a spread of P–O bond distances ranging from 1.51–1.60 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one MnO6 octahedra, corners with three CrO6 octahedra, and an edgeedge with one MnO6 octahedra. The corner-sharing octahedra tilt angles range from 40–54°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one MnO6 octahedra, corners with three CrO6 octahedra, and an edgeedge with one CrO6 octahedra. The corner-sharing octahedra tilt angles range from 46–57°. There are a spread of P–O bond distances ranging from 1.52–1.59 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr+3.33+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cr+3.33+, one Mn2+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr+3.33+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Mn2+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+3.33+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr+3.33+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+3.33+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Cr+3.33+, one Mn2+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr+3.33+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr+3.33+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+3.33+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mn2+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr3Ni(PO4)4 by Materials Project

Cr3Ni(PO4)4 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are three inequivalent Cr+3.33+ sites. In the first Cr+3.33+ site, Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Cr–O bond distances ranging from 1.95–2.07 Å. In the second Cr+3.33+ site, Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent NiO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–50°. There are a spread of Cr–O bond distances ranging from 1.97–2.04 Å. In the third Cr+3.33+ site, Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Cr–O bond distances ranging from 1.97–2.09 Å. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–50°. There are a spread of Ni–O bond distances ranging from 1.98–2.21 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two CrO6 octahedra, corners with two equivalent NiO6 octahedra, and an edgeedge with one CrO6 octahedra. The corner-sharing octahedra tilt angles range from 41–59°. There is two shorter (1.52 Å) and two longer (1.58 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four CrO6 octahedra and an edgeedge with one CrO6 octahedra. The corner-sharing octahedra tilt angles range from 45–57°. There is two shorter (1.52 Å) and two longer (1.59 Å) P–O bond length. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one NiO6 octahedra, corners with three CrO6 octahedra, and an edgeedge with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 46–54°. There are a spread of P–O bond distances ranging from 1.51–1.59 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one NiO6 octahedra, corners with three CrO6 octahedra, and an edgeedge with one CrO6 octahedra. The corner-sharing octahedra tilt angles range from 44–57°. There are a spread of P–O bond distances ranging from 1.50–1.60 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr+3.33+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cr+3.33+, one Ni2+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr+3.33+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Ni2+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+3.33+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr+3.33+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr+3.33+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Cr+3.33+, one Ni2+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr+3.33+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr+3.33+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+3.33+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ni2+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on U2Cr3Si by Materials Project

U2Cr3Si crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. U is bonded in a 10-coordinate geometry to one U, nine Cr, and three equivalent Si atoms. The U–U bond length is 2.63 Å. There are a spread of U–Cr bond distances ranging from 2.87–3.07 Å. There are one shorter (3.02 Å) and two longer (3.03 Å) U–Si bond lengths. There are three inequivalent Cr sites. In the first Cr site, Cr is bonded to six equivalent U, four Cr, and two equivalent Si atoms to form distorted CrU6Cr4Si2 cuboctahedra that share corners with four equivalent SiU6Cr6 cuboctahedra, corners with fourteen CrU6Cr4Si2 cuboctahedra, edges with six equivalent CrU6Cr4Si2 cuboctahedra, faces with six equivalent SiU6Cr6 cuboctahedra, and faces with twelve CrU6Cr4Si2 cuboctahedra. There are a spread of Cr–Cr bond distances ranging from 2.46–2.64 Å. Both Cr–Si bond lengths are 2.53 Å. In the second Cr site, Cr is bonded to six equivalent U, four Cr, and two equivalent Si atoms to form distorted CrU6Cr4Si2 cuboctahedra that share corners with four equivalent SiU6Cr6 cuboctahedra, corners with fourteen CrU6Cr4Si2 cuboctahedra, edges with six equivalent CrU6Cr4Si2 cuboctahedra, faces with six equivalent SiU6Cr6 cuboctahedra, and faces with twelve CrU6Cr4Si2 cuboctahedra. There are one shorter (2.47 Å) and one longer (2.63 Å) Cr–Cr bond lengths. Both Cr–Si bond lengths are 2.53 Å. In the third Cr site, Cr is bonded to six equivalent U, four Cr, and two equivalent Si atoms to form distorted CrU6Cr4Si2 cuboctahedra that share corners with four equivalent SiU6Cr6 cuboctahedra, corners with fourteen CrU6Cr4Si2 cuboctahedra, edges with six equivalent CrU6Cr4Si2 cuboctahedra, faces with six equivalent SiU6Cr6 cuboctahedra, and faces with twelve CrU6Cr4Si2 cuboctahedra. Both Cr–Si bond lengths are 2.53 Å. Si is bonded to six equivalent U and six Cr atoms to form SiU6Cr6 cuboctahedra that share corners with twelve CrU6Cr4Si2 cuboctahedra, edges with six equivalent SiU6Cr6 cuboctahedra, faces with two equivalent SiU6Cr6 cuboctahedra, and faces with eighteen CrU6Cr4Si2 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiCr3P3O13 by Materials Project

LiCr3P3O13 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Li1+ is bonded to five O2- atoms to form LiO5 square pyramids that share corners with five CrO6 octahedra, corners with three equivalent PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–61°. There are a spread of Li–O bond distances ranging from 1.96–2.38 Å. There are three inequivalent Cr+3.33+ sites. In the first Cr+3.33+ site, Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with two equivalent CrO6 octahedra, a cornercorner with one CrO5 square pyramid, corners with three equivalent LiO5 square pyramids, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Cr–O bond distances ranging from 1.87–2.10 Å. In the second Cr+3.33+ site, Cr+3.33+ is bonded to five O2- atoms to form CrO5 square pyramids that share a cornercorner with one CrO6 octahedra and corners with five PO4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. There are a spread of Cr–O bond distances ranging from 1.91–2.01 Å. In the third Cr+3.33+ site, Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with two equivalent CrO6 octahedra, corners with two equivalent LiO5 square pyramids, corners with four PO4 tetrahedra, and edges with two equivalent CrO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Cr–O bond distances ranging from 2.00–2.06 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CrO6 octahedra and corners with three equivalent CrO5 square pyramids. The corner-sharing octahedral tilt angles are 29°. There is three shorter (1.54 Å) and one longer (1.55 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four CrO6 octahedra, a cornercorner with one CrO5 square pyramid, and an edgeedge with one LiO5 square pyramid. The corner-sharing octahedra tilt angles range from 43–55°. There are a spread of P–O bond distances ranging from 1.52–1.60 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CrO6 octahedra, a cornercorner with one CrO5 square pyramid, corners with three equivalent LiO5 square pyramids, and an edgeedge with one CrO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cr+3.33+ and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Cr+3.33+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr+3.33+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+3.33+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Cr+3.33+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+3.33+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to three Cr+3.33+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+3.33+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Cr+3.33+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Cr+3.33+, and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ZrTiCr4 by Materials Project

ZrTiCr4 is Hexagonal Laves-derived structured and crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Zr is bonded in a 12-coordinate geometry to three equivalent Zr, one Ti, and twelve Cr atoms. All Zr–Zr bond lengths are 3.07 Å. The Zr–Ti bond length is 3.01 Å. There are three shorter (2.93 Å) and nine longer (2.94 Å) Zr–Cr bond lengths. Ti is bonded in a 10-coordinate geometry to one Zr, three equivalent Ti, and twelve Cr atoms. All Ti–Ti bond lengths are 3.02 Å. There are a spread of Ti–Cr bond distances ranging from 2.75–2.92 Å. There are three inequivalent Cr sites. In the first Cr site, Cr is bonded to six equivalent Ti and six equivalent Cr atoms to form CrTi6Cr6 cuboctahedra that share corners with twelve equivalent CrZr3Ti3Cr6 cuboctahedra, edges with six equivalent CrTi6Cr6 cuboctahedra, and faces with twenty CrZr6Cr6 cuboctahedra. All Cr–Cr bond lengths are 2.41 Å. In the second Cr site, Cr is bonded to six equivalent Zr and six equivalent Cr atoms to form CrZr6Cr6 cuboctahedra that share corners with twelve equivalent CrZr3Ti3Cr6 cuboctahedra, edges with six equivalent CrZr6Cr6 cuboctahedra, and faces with twenty CrTi6Cr6 cuboctahedra. All Cr–Cr bond lengths are 2.53 Å. In the third Cr site, Cr is bonded to three equivalent Zr, three equivalent Ti, and six Cr atoms to form CrZr3Ti3Cr6 cuboctahedra that share corners with eighteen CrTi6Cr6 cuboctahedra, edges with six equivalent CrZr3Ti3Cr6 cuboctahedra, and faces with eighteen CrTi6Cr6 cuboctahedra. There are two shorter (2.46 Å) and two longer (2.54 Å) Cr–Cr bond lengths.

36 MATERIALS SCIENCE↗