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DOE OSTI2020

Materials Data on Li3Cr5O8 by Materials Project

Li3Cr5O8 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six equivalent CrO6 octahedra, edges with four equivalent LiO6 octahedra, and edges with eight CrO6 octahedra. The corner-sharing octahedra tilt angles range from 3–6°. There are four shorter (2.19 Å) and two longer (2.21 Å) Li–O bond lengths. There are three inequivalent Cr+2.60+ sites. In the first Cr+2.60+ site, Cr+2.60+ is bonded to six equivalent O2- atoms to form CrO6 octahedra that share corners with six equivalent CrO6 octahedra, edges with six equivalent LiO6 octahedra, and edges with six equivalent CrO6 octahedra. The corner-sharing octahedral tilt angles are 4°. All Cr–O bond lengths are 2.11 Å. In the second Cr+2.60+ site, Cr+2.60+ is bonded to six equivalent O2- atoms to form CrO6 octahedra that share corners with six equivalent CrO6 octahedra, edges with six equivalent LiO6 octahedra, and edges with six equivalent CrO6 octahedra. The corner-sharing octahedral tilt angles are 4°. All Cr–O bond lengths are 2.15 Å. In the third Cr+2.60+ site, Cr+2.60+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six equivalent LiO6 octahedra, edges with four equivalent LiO6 octahedra, and edges with eight CrO6 octahedra. The corner-sharing octahedra tilt angles range from 3–6°. There are two shorter (2.05 Å) and four longer (2.07 Å) Cr–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Li1+ and three equivalent Cr+2.60+ atoms to form OLi3Cr3 octahedra that share corners with six equivalent OLi3Cr3 octahedra and edges with twelve equivalent OLi2Cr4 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded to two equivalent Li1+ and four Cr+2.60+ atoms to form OLi2Cr4 octahedra that share corners with six equivalent OLi2Cr4 octahedra and edges with twelve OLi3Cr3 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HfCrGe2 by Materials Project

HfCrGe2 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are two inequivalent Hf sites. In the first Hf site, Hf is bonded in a 8-coordinate geometry to eight Ge atoms. There are a spread of Hf–Ge bond distances ranging from 2.75–3.00 Å. In the second Hf site, Hf is bonded in a 7-coordinate geometry to seven Ge atoms. There are a spread of Hf–Ge bond distances ranging from 2.77–2.88 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a 12-coordinate geometry to six Ge atoms. There are a spread of Cr–Ge bond distances ranging from 2.45–2.58 Å. In the second Cr site, Cr is bonded to six Ge atoms to form distorted edge-sharing CrGe6 cuboctahedra. There are a spread of Cr–Ge bond distances ranging from 2.51–2.59 Å. There are five inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to six Hf, two equivalent Cr, and one Ge atom. The Ge–Ge bond length is 2.54 Å. In the second Ge site, Ge is bonded in a 2-coordinate geometry to four equivalent Hf, two equivalent Cr, and one Ge atom. The Ge–Ge bond length is 2.60 Å. In the third Ge site, Ge is bonded in a 9-coordinate geometry to five Hf and four Cr atoms. In the fourth Ge site, Ge is bonded in a 6-coordinate geometry to two equivalent Hf and four Cr atoms. In the fifth Ge site, Ge is bonded in a 7-coordinate geometry to three Hf, three Cr, and one Ge atom. The Ge–Ge bond length is 2.57 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li2MnCr3O8 by Materials Project

Li2Cr3MnO8 is Spinel-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three MnO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 1.98–2.02 Å. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three MnO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 1.98–2.02 Å. In the third Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three MnO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 1.98–2.02 Å. In the fourth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three MnO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 1.98–2.02 Å. In the fifth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three MnO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 1.98–2.02 Å. In the sixth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three MnO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 1.99–2.02 Å. In the seventh Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three MnO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 1.98–2.03 Å. In the eighth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three MnO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 1.98–2.02 Å. There are twelve inequivalent Cr4+ sites. In the first Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.01–2.04 Å. In the second Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.91–2.00 Å. In the third Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.01–2.04 Å. In the fourth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.01–2.04 Å. In the fifth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.91–1.99 Å. In the sixth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.01–2.04 Å. In the seventh Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.01–2.04 Å. In the eighth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.91–2.00 Å. In the ninth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.01–2.04 Å. In the tenth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.01–2.04 Å. In the eleventh Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.91–2.00 Å. In the twelfth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two MnO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.01–2.05 Å. There are four inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six LiO4 tetrahedra and edges with six CrO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.94–1.96 Å. In the second Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six LiO4 tetrahedra and edges with six CrO6 octahedra. There is two shorter (1.94 Å) and four longer (1.95 Å) Mn–O bond length. In the third Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six LiO4 tetrahedra and edges with six CrO6 octahedra. There is two shorter (1.94 Å) and four longer (1.95 Å) Mn–O bond length. In the fourth Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six LiO4 tetrahedra and edges with six CrO6 octahedra. There is two shorter (1.94 Å) and four longer (1.95 Å) Mn–O bond length. There are thirty-two inequivalent O2- sites. In the first O2- site, O2- is bonded to one Li1+, two Cr4+, and one Mn2+ atom to form distorted corner-sharing OLiMnCr2 trigonal pyramids. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the eighth O2- site, O2- is bonded to one Li1+, two Cr4+, and one Mn2+ atom to form distorted corner-sharing OLiMnCr2 trigonal pyramids. In the ninth O2- site, O2- is bonded to one Li1+, two Cr4+, and one Mn2+ atom to form distorted corner-sharing OLiMnCr2 trigonal pyramids. In the tenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the eleventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the thirteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the fourteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the sixteenth O2- site, O2- is bonded to one Li1+, two Cr4+, and one Mn2+ atom to form distorted corner-sharing OLiMnCr2 trigonal pyramids. In the seventeenth O2- site, O2- is bonded to one Li1+, two Cr4+, and one Mn2+ atom to form distorted corner-sharing OLiMnCr2 trigonal pyramids. In the eighteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the nineteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the twentieth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the twenty-first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the twenty-second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the twenty-third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the twenty-fourth O2- site, O2- is bonded to one Li1+, two Cr4+, and one Mn2+ atom to form distorted corner-sharing OLiMnCr2 trigonal pyramids. In the twenty-fifth O2- site, O2- is bonded to one Li1+, two Cr4+, and one Mn2+ atom to form distorted corner-sharing OLiMnCr2 trigonal pyramids. In the twenty-sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the twenty-seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the twenty-eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the twenty-ninth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the thirtieth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the thirty-first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Mn2+ atom. In the thirty-second O2- site, O2- is bonded to one Li1+, two Cr4+, and one Mn2+ atom to form distorted corner-sharing OLiMnCr2 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ScCrGe2 by Materials Project

ScCrGe2 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are two inequivalent Sc sites. In the first Sc site, Sc is bonded in a 8-coordinate geometry to eight Ge atoms. There are a spread of Sc–Ge bond distances ranging from 2.78–2.99 Å. In the second Sc site, Sc is bonded in a 7-coordinate geometry to seven Ge atoms. There are a spread of Sc–Ge bond distances ranging from 2.78–2.93 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a 12-coordinate geometry to six Ge atoms. There are a spread of Cr–Ge bond distances ranging from 2.48–2.60 Å. In the second Cr site, Cr is bonded in a 12-coordinate geometry to six Ge atoms. There are a spread of Cr–Ge bond distances ranging from 2.56–2.58 Å. There are five inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to six Sc, two equivalent Cr, and one Ge atom. The Ge–Ge bond length is 2.56 Å. In the second Ge site, Ge is bonded in a 2-coordinate geometry to four equivalent Sc, two equivalent Cr, and one Ge atom. The Ge–Ge bond length is 2.61 Å. In the third Ge site, Ge is bonded in a 9-coordinate geometry to five Sc and four Cr atoms. In the fourth Ge site, Ge is bonded in a 6-coordinate geometry to two equivalent Sc and four Cr atoms. In the fifth Ge site, Ge is bonded in a 7-coordinate geometry to three Sc, three Cr, and one Ge atom. The Ge–Ge bond length is 2.61 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm4CrFe33 by Materials Project

Sm4CrFe33 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Sm sites. In the first Sm site, Sm is bonded in a 9-coordinate geometry to one Cr and eighteen Fe atoms. The Sm–Cr bond length is 3.15 Å. There are a spread of Sm–Fe bond distances ranging from 3.02–3.30 Å. In the second Sm site, Sm is bonded in a 10-coordinate geometry to nineteen Fe atoms. There are a spread of Sm–Fe bond distances ranging from 3.02–3.28 Å. In the third Sm site, Sm is bonded in a 10-coordinate geometry to nineteen Fe atoms. There are a spread of Sm–Fe bond distances ranging from 3.02–3.29 Å. In the fourth Sm site, Sm is bonded in a 10-coordinate geometry to nineteen Fe atoms. There are a spread of Sm–Fe bond distances ranging from 3.02–3.29 Å. Cr is bonded in a 1-coordinate geometry to one Sm and thirteen Fe atoms. There are a spread of Cr–Fe bond distances ranging from 2.30–2.76 Å. There are twenty-one inequivalent Fe sites. In the first Fe site, Fe is bonded in a 12-coordinate geometry to two Sm and ten Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.44–2.77 Å. In the second Fe site, Fe is bonded in a 12-coordinate geometry to two Sm, one Cr, and nine Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.43–2.77 Å. In the third Fe site, Fe is bonded in a 12-coordinate geometry to two Sm and ten Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.44–2.76 Å. In the fourth Fe site, Fe is bonded in a 12-coordinate geometry to two Sm, one Cr, and nine Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.43–2.75 Å. In the fifth Fe site, Fe is bonded in a 12-coordinate geometry to two Sm, one Cr, and nine Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.43–2.75 Å. In the sixth Fe site, Fe is bonded in a 12-coordinate geometry to two Sm and ten Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.44–2.76 Å. In the seventh Fe site, Fe is bonded to two Sm, one Cr, and nine Fe atoms to form a mixture of distorted face, edge, and corner-sharing FeSm2CrFe9 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.45–2.63 Å. In the eighth Fe site, Fe is bonded to two Sm and ten Fe atoms to form a mixture of face, edge, and corner-sharing FeSm2Fe10 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.46–2.62 Å. In the ninth Fe site, Fe is bonded to two Sm, one Cr, and nine Fe atoms to form a mixture of distorted face, edge, and corner-sharing FeSm2CrFe9 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.44–2.64 Å. In the tenth Fe site, Fe is bonded to two Sm and ten Fe atoms to form FeSm2Fe10 cuboctahedra that share corners with fourteen FeSm3CrFe8 cuboctahedra, edges with six FeSm3CrFe8 cuboctahedra, and faces with ten FeSm3Fe9 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.46–2.62 Å. In the eleventh Fe site, Fe is bonded to three Sm and nine Fe atoms to form a mixture of face, edge, and corner-sharing FeSm3Fe9 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.47–2.65 Å. In the twelfth Fe site, Fe is bonded to three Sm and nine Fe atoms to form FeSm3Fe9 cuboctahedra that share corners with fifteen FeSm3CrFe8 cuboctahedra, edges with eight FeSm3Fe9 cuboctahedra, and faces with ten FeSm3Fe9 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.47–2.66 Å. In the thirteenth Fe site, Fe is bonded to three Sm and nine Fe atoms to form FeSm3Fe9 cuboctahedra that share corners with fifteen FeSm3CrFe8 cuboctahedra, edges with eight FeSm3Fe9 cuboctahedra, and faces with ten FeSm3CrFe8 cuboctahedra. There are two shorter (2.48 Å) and one longer (2.66 Å) Fe–Fe bond lengths. In the fourteenth Fe site, Fe is bonded to three Sm and nine Fe atoms to form FeSm3Fe9 cuboctahedra that share corners with fifteen FeSm3CrFe8 cuboctahedra, edges with eight FeSm3CrFe8 cuboctahedra, and faces with ten FeSm3Fe9 cuboctahedra. There are two shorter (2.49 Å) and one longer (2.64 Å) Fe–Fe bond lengths. In the fifteenth Fe site, Fe is bonded to three Sm, one Cr, and eight Fe atoms to form a mixture of face, edge, and corner-sharing FeSm3CrFe8 cuboctahedra. In the sixteenth Fe site, Fe is bonded to three Sm and nine Fe atoms to form a mixture of face, edge, and corner-sharing FeSm3Fe9 cuboctahedra. The Fe–Fe bond length is 2.65 Å. In the seventeenth Fe site, Fe is bonded to three Sm and nine Fe atoms to form FeSm3Fe9 cuboctahedra that share corners with fifteen FeSm3CrFe8 cuboctahedra, edges with eight FeSm3CrFe8 cuboctahedra, and faces with ten FeSm3Fe9 cuboctahedra. The Fe–Fe bond length is 2.65 Å. In the eighteenth Fe site, Fe is bonded to three Sm, one Cr, and eight Fe atoms to form FeSm3CrFe8 cuboctahedra that share corners with fifteen FeSm3Fe9 cuboctahedra, edges with eight FeSm3CrFe8 cuboctahedra, and faces with ten FeSm3CrFe8 cuboctahedra. In the nineteenth Fe site, Fe is bonded in a 2-coordinate geometry to one Sm and thirteen Fe atoms. The Fe–Fe bond length is 2.39 Å. In the twentieth Fe site, Fe is bonded in a 2-coordinate geometry to one Sm and thirteen Fe atoms. In the twenty-first Fe site, Fe is bonded in a distorted single-bond geometry to one Sm, one Cr, and twelve Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr3As by Materials Project

Cr3As is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Cr sites. In the first Cr site, Cr is bonded to eight Cr and four equivalent As atoms to form distorted CrCr8As4 cuboctahedra that share corners with twelve equivalent CrCr8As4 cuboctahedra, edges with eight equivalent CrCr8As4 cuboctahedra, edges with eight equivalent AsCr12 cuboctahedra, faces with four equivalent AsCr12 cuboctahedra, and faces with ten equivalent CrCr8As4 cuboctahedra. There are four shorter (2.45 Å) and four longer (2.68 Å) Cr–Cr bond lengths. All Cr–As bond lengths are 2.68 Å. In the second Cr site, Cr is bonded in a square co-planar geometry to eight equivalent Cr and four equivalent As atoms. All Cr–As bond lengths are 2.45 Å. As is bonded to twelve Cr atoms to form AsCr12 cuboctahedra that share corners with four equivalent AsCr12 cuboctahedra, edges with eight equivalent AsCr12 cuboctahedra, edges with sixteen equivalent CrCr8As4 cuboctahedra, faces with four equivalent AsCr12 cuboctahedra, and faces with eight equivalent CrCr8As4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li2Cr3CoO8 by Materials Project

Li2Cr3CoO8 is Spinel-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three CoO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 55–63°. There is three shorter (1.98 Å) and one longer (2.01 Å) Li–O bond length. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three CoO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 54–63°. There is one shorter (1.96 Å) and three longer (1.99 Å) Li–O bond length. In the third Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three CoO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 1.99–2.02 Å. In the fourth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three CoO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 1.97–1.99 Å. In the fifth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three CoO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 54–64°. There are a spread of Li–O bond distances ranging from 1.97–2.02 Å. In the sixth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three CoO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 54–64°. There are three shorter (1.97 Å) and one longer (2.04 Å) Li–O bond lengths. In the seventh Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three CoO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 55–65°. There are a spread of Li–O bond distances ranging from 1.97–2.00 Å. In the eighth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three CoO6 octahedra and corners with nine CrO6 octahedra. The corner-sharing octahedra tilt angles range from 54–67°. There are a spread of Li–O bond distances ranging from 1.98–2.01 Å. There are twelve inequivalent Cr4+ sites. In the first Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.90–2.01 Å. In the second Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are four shorter (2.01 Å) and two longer (2.03 Å) Cr–O bond lengths. In the third Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.99–2.07 Å. In the fourth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.00–2.05 Å. In the fifth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.90–2.00 Å. In the sixth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.00–2.04 Å. In the seventh Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.01–2.05 Å. In the eighth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.00–2.04 Å. In the ninth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.91–1.99 Å. In the tenth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.92–2.01 Å. In the eleventh Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.00–2.06 Å. In the twelfth Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six LiO4 tetrahedra, edges with two CoO6 octahedra, and edges with four CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.00–2.05 Å. There are four inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six LiO4 tetrahedra and edges with six CrO6 octahedra. There are a spread of Co–O bond distances ranging from 1.88–1.95 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six LiO4 tetrahedra and edges with six CrO6 octahedra. There are a spread of Co–O bond distances ranging from 1.89–1.93 Å. In the third Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six LiO4 tetrahedra and edges with six CrO6 octahedra. There are a spread of Co–O bond distances ranging from 1.89–1.94 Å. In the fourth Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six LiO4 tetrahedra and edges with six CrO6 octahedra. There are a spread of Co–O bond distances ranging from 1.89–1.96 Å. There are thirty-two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the second O2- site, O2- is bonded to one Li1+, two Cr4+, and one Co2+ atom to form distorted corner-sharing OLiCr2Co tetrahedra. In the third O2- site, O2- is bonded to one Li1+ and three Cr4+ atoms to form distorted corner-sharing OLiCr3 trigonal pyramids. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the ninth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the tenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the eleventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the thirteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to one Li1+ and three Cr4+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the sixteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the seventeenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the eighteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the nineteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the twentieth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the twenty-first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the twenty-second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the twenty-third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the twenty-fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the twenty-fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the twenty-sixth O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to one Li1+, two Cr4+, and one Co2+ atom. In the twenty-seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the twenty-eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the twenty-ninth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the thirtieth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr4+ atoms. In the thirty-first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom. In the thirty-second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Cr4+, and one Co2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CrN2 by Materials Project

CrN2 is Low Tridymite structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are twelve inequivalent Cr6+ sites. In the first Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.70–1.78 Å. In the second Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.70–1.78 Å. In the third Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.67–1.75 Å. In the fourth Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.68–1.76 Å. In the fifth Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.70–1.78 Å. In the sixth Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.69–1.77 Å. In the seventh Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.68–1.75 Å. In the eighth Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.67–1.75 Å. In the ninth Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.70–1.78 Å. In the tenth Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.67–1.76 Å. In the eleventh Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.67–1.76 Å. In the twelfth Cr6+ site, Cr6+ is bonded to four N3- atoms to form corner-sharing CrN4 tetrahedra. There are a spread of Cr–N bond distances ranging from 1.69–1.78 Å. There are twenty-four inequivalent N3- sites. In the first N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the second N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the third N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the fourth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the fifth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the sixth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the seventh N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the eighth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the ninth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the tenth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the eleventh N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the twelfth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the thirteenth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the fourteenth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the fifteenth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the sixteenth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the seventeenth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the eighteenth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the nineteenth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the twentieth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the twenty-first N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the twenty-second N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the twenty-third N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms. In the twenty-fourth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm2Cr(Fe8C)2 by Materials Project

Sm2Cr(Fe8C)2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent Sm sites. In the first Sm site, Sm is bonded in a distorted bent 120 degrees geometry to eight Fe and two equivalent C atoms. There are a spread of Sm–Fe bond distances ranging from 3.06–3.40 Å. Both Sm–C bond lengths are 2.53 Å. In the second Sm site, Sm is bonded in a distorted bent 120 degrees geometry to one Cr, eight Fe, and two equivalent C atoms. The Sm–Cr bond length is 3.22 Å. There are a spread of Sm–Fe bond distances ranging from 3.02–3.44 Å. Both Sm–C bond lengths are 2.54 Å. Cr is bonded in a 1-coordinate geometry to one Sm and thirteen Fe atoms. There are a spread of Cr–Fe bond distances ranging from 2.31–2.74 Å. There are ten inequivalent Fe sites. In the first Fe site, Fe is bonded to three Sm, one Cr, and eight Fe atoms to form distorted FeSm3CrFe8 cuboctahedra that share corners with eleven FeSm3CrFe8 cuboctahedra, corners with four equivalent CSm2Fe4 octahedra, edges with four FeSm3Fe9 cuboctahedra, faces with eight FeSm3Fe9 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 63–71°. There are a spread of Fe–Fe bond distances ranging from 2.45–2.69 Å. In the second Fe site, Fe is bonded in a single-bond geometry to one Cr, four Fe, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.45–2.58 Å. The Fe–C bond length is 1.92 Å. In the third Fe site, Fe is bonded to three Sm and nine Fe atoms to form distorted FeSm3Fe9 cuboctahedra that share corners with eleven FeSm3CrFe8 cuboctahedra, corners with four equivalent CSm2Fe4 octahedra, edges with four FeSm3CrFe8 cuboctahedra, faces with eight FeSm3CrFe8 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 62–69°. There are a spread of Fe–Fe bond distances ranging from 2.47–2.68 Å. In the fourth Fe site, Fe is bonded in a single-bond geometry to four Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.45–2.57 Å. The Fe–C bond length is 1.92 Å. In the fifth Fe site, Fe is bonded in a single-bond geometry to one Cr, four Fe, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.44–2.46 Å. The Fe–C bond length is 1.85 Å. In the sixth Fe site, Fe is bonded in a single-bond geometry to one Cr, four Fe, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.43–2.48 Å. The Fe–C bond length is 1.86 Å. In the seventh Fe site, Fe is bonded to two Sm, one Cr, and nine Fe atoms to form distorted FeSm2CrFe9 cuboctahedra that share corners with eight FeSm3CrFe8 cuboctahedra, corners with four equivalent CSm2Fe4 octahedra, edges with three FeSm2CrFe9 cuboctahedra, edges with two equivalent CSm2Fe4 octahedra, and faces with nine FeSm3CrFe8 cuboctahedra. The corner-sharing octahedra tilt angles range from 22–28°. There are a spread of Fe–Fe bond distances ranging from 2.44–2.70 Å. In the eighth Fe site, Fe is bonded to two Sm, one Cr, and nine Fe atoms to form distorted FeSm2CrFe9 cuboctahedra that share corners with eight FeSm3CrFe8 cuboctahedra, corners with two equivalent CSm2Fe4 octahedra, edges with four FeSm3CrFe8 cuboctahedra, faces with eight FeSm3CrFe8 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 46–48°. The Fe–Fe bond length is 2.67 Å. In the ninth Fe site, Fe is bonded to two Sm, one Cr, and nine Fe atoms to form distorted FeSm2CrFe9 cuboctahedra that share corners with fourteen FeSm3CrFe8 cuboctahedra, edges with two FeSm3Fe9 cuboctahedra, faces with ten FeSm3CrFe8 cuboctahedra, and faces with four equivalent CSm2Fe4 octahedra. The Fe–Fe bond length is 2.68 Å. In the tenth Fe site, Fe is bonded in a distorted single-bond geometry to one Cr and six Fe atoms. C is bonded to two Sm and four Fe atoms to form CSm2Fe4 octahedra that share corners with ten FeSm3CrFe8 cuboctahedra, corners with two equivalent CSm2Fe4 octahedra, edges with two equivalent FeSm2CrFe9 cuboctahedra, and faces with six FeSm3Fe9 cuboctahedra. The corner-sharing octahedra tilt angles range from 63–64°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zr3(CrGa3)2 by Materials Project

Zr3(CrGa3)2 crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. there are two inequivalent Zr sites. In the first Zr site, Zr is bonded in a 11-coordinate geometry to two equivalent Cr and nine Ga atoms. Both Zr–Cr bond lengths are 3.02 Å. There are a spread of Zr–Ga bond distances ranging from 2.84–3.05 Å. In the second Zr site, Zr is bonded in a 7-coordinate geometry to four equivalent Cr and seven Ga atoms. All Zr–Cr bond lengths are 3.08 Å. There are a spread of Zr–Ga bond distances ranging from 2.72–2.93 Å. Cr is bonded to four Zr, two equivalent Cr, and six Ga atoms to form a mixture of distorted edge, face, and corner-sharing CrZr4Cr2Ga6 cuboctahedra. Both Cr–Cr bond lengths are 2.68 Å. There are a spread of Cr–Ga bond distances ranging from 2.52–2.78 Å. There are four inequivalent Ga sites. In the first Ga site, Ga is bonded in a 9-coordinate geometry to four Zr, two equivalent Cr, and two equivalent Ga atoms. Both Ga–Ga bond lengths are 2.64 Å. In the second Ga site, Ga is bonded in a 1-coordinate geometry to three Zr, four equivalent Cr, and two equivalent Ga atoms. Both Ga–Ga bond lengths are 2.84 Å. In the third Ga site, Ga is bonded in a 12-coordinate geometry to four Zr and four equivalent Cr atoms. In the fourth Ga site, Ga is bonded in a 10-coordinate geometry to five Zr and five Ga atoms. There are one shorter (2.57 Å) and one longer (2.79 Å) Ga–Ga bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Phase stability, mechanical properties, and ion irradiation effects in face-centered cubic CrFeMnNi compositionally complex solid-solution alloys at high temperatures

We report two CrFeMnNi face-centered cubic complex concentrated solid-solution alloys (CSA) have been evaluated for phase stability, mechanical properties, and radiation damage effects from heavy ions. Cr 18 Fe 27 Mn 27 Ni 28 and Cr 15 Fe 35 Mn 15 Ni 35 were predicted by thermodynamic calculations to phase separate and maintain a single phase at 700 °C, respectively. Aging experiments at this temperature confirmed varying degrees of precipitation of a body-centered cubic phase in both Cr 18 Fe 27 Mn 27 Ni 28 and Cr 15 Fe 35 Mn 15 Ni 35 . The alloys showed promising strength in tensile deformation at room temperature, with yield strengths of 155 MPa and 151 MPa for Cr 18 Fe 27 Mn 27 Ni 28 and Cr 15 Fe3 5 Mn 15 Ni 35 , respectively. At 500 °C, the yield strength of Cr 18 Fe 27 Mn 27 Ni 28 fell to 93 MPa, and to 100 MPa in Cr 15 Fe3 5 Mn 15 Ni 35 . Unlike Cr 18 Fe 27 Mn 27 Ni 28 , Cr 15 Fe 35 Mn 15 Ni 35 gained some ductility at 500 °C compared to room temperature. The two CSAs were irradiated to 75 dpa at 500 °C in the plateau region of the displacement curve using 3.7 MeV Ni 2+ ions, alongside model alloy 709 as a reference. Irradiation results produced similar densities and sizes of dislocations loops in the two CSAs compared to the reference. However, while large voids form in the plateau region of Cr 18 Fe 27 Mn 27 Ni 28 , small voids form just beyond the displacement peak of Cr 15 Fe 35 Mn 15 Ni 35 . Atom probe tomography and energy dispersive X-ray spectroscopy-equipped scanning transmission electron microscopes were used to characterize the alloys for changes in chemical distribution.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2022

Mechanistic insights into sulfate and phosphate-mediated hexavalent chromium removal by tea polyphenols wrapped nano-zero-valent iron

Nano zero-valent iron via green synthesis (g-nZVI) has great potential in removing toxic hexavalent Cr(VI) from industrial wastewater. Sulfate and phosphate in wastewater can influence Cr(VI) removal by g-nZVI. Here, in this study, the Cr(VI) removal kinetics by different g-nZVI materials were investigated with the existence of sulfate and/or phosphate, and the corresponding mechanisms were first revealed using multiple characterizations, including X-ray absorption near-edge spectra (XANES) and X-ray photoelectron spectroscopy (XPS). The results showed that Cr(OH) 3 was the dominant species initially formed on the surface of g-nZVI particles before transforming to Cr 2 O 3 during the reaction of g-nZVI with Cr(VI). Sulfate in wastewater can promote the reduction from Cr(VI) to Cr(OH) 3 by g-nZVI, because sulfate triggers the release of Fe(II) and tea polyphenols (from tea extracts) from the g-nZVI surface due to the corrosion of Fe 0 core, which is in line with an obvious increase in pseudo-second-order rate constant (k 2 ) and subtle change in Cr(VI) removal capacity (q e ). However, phosphate impedes the g-nZVI corrosion and inhibits q e because of the inner-sphere complexation of phosphate onto g-nZVI decreasing the released Fe(II) for Cr 2 O 3 production. When sulfate and phosphate coexisted in contaminated water, the inhibition effect of phosphate in Cr(VI) removal by g-nZVI was stronger than the promotion of sulfate. Accordingly, q e value of g-nZVI declined from 93.4 mg g –1 to 77.5 mg g –1 , while k 2 remained constant as the molar ratio of phosphate/sulfate increased from 0.1 to 10 in water. This study provides new insights into applying g-nZVI in efficient Cr(VI) removal from contaminated water with enrichment of sulphates and phosphates.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Weakening the N–H Bonds of NH 3 Ligands: Triple Hydrogen-Atom Abstraction to Form a Chromium(V) Nitride

Weakening and cleaving N-H bonds is crucial for improving molecular ammonia oxidation catalysts. In this work, we report the synthesis and hydrogen atom abstraction chemistry of bis(ammonia) Cr porphyrin complexes Cr(TPP)(NH 3 ) 2 and Cr(TMP)(NH 3 ) 2 (TPP = 5,10,15,20-tetraphenyl-meso-porphyrin and TMP = 5,10,15,20-tetramesityl-meso-porphyrin) using bulky aryloxyl radicals. The triple hydrogen atom abstraction reaction results in the formation of Cr V (por)(≡N), with the nitride deriving from ammonia, as indicated by UV-Vis and FT-IR spectroscopy, and a single crystal structural determination of Cr(TPP)(≡N). Subsequent oxidation of this chromium(V)-nitrido complex results in the formation of Cr III (por), with scission of the Cr≡N bond. A computational analysis illustrates the progression from Cr II to Cr V and evaluates the energetics of abstracting hydrogen atoms from Cr II -NH 3 to generate Cr V ≡N. The formation and isolation of Cr V (por)(≡N) illustrates the stability of these species and the need to chemically activate the nitride moiety for atom transfer or N-N coupling reactivity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Insights on the corrosion thermodynamics of chromium in molten LiF-NaF-KF eutectic salts

The thermodynamic stability of chromium in the Cr 0 , Cr 2+ , and Cr 3+ oxidation states considering various F - ion coordination compounds was investigated in molten LiF–NaF-KF (FLiNaK) eutectic salt. Potential fluoride ion activity (F - and CrF 3 - ) diagrams were constructed to predict the most stable Cr oxidation states as a function of anion activity, solvation state of chromium ions and potential at 600 °C. The Gibbs free energies of these compounds were estimated by utilizing a combined cyclic voltammetry – Nernst theory analysis approach in FLiNaK salt. To verify the constructed diagrams, X-ray diffraction was utilized after exposure of Cr at various applied potentials to determine whether compounds detected in solidified FLiNaK salts agreed with thermodynamic calculations. This work aims to identify key thermodynamic factors that are significant to chromium corrosion for molten salt nuclear reactor applications. The F - stability region spans the entire region where spontaneous corrosion of Cr occurs. Cr may be oxidized to Cr 2+ and Cr 3+ in the presence HF (due to moisture as an impurity) spontaneously except some conditions of p 1/2 H 2 /a HF etc. This situation is not changed qualitatively for various states of solvation between oxidized Cr solute in F - solvent and this aspect is substantially similar for the two cases (pair 1: Cr 0 /CrF 3 - / CrF 6 3- ; pair 2: Cr 0 /CrF 4 2- /CrF 5 2- ) considered in this work.

36 MATERIALS SCIENCE↗
NASA NTRS1998

Fluorescence of Pentavalent Chromium in SiO2 Sol-Gel Glasses

Chromium ions are very attractive to optical spectroscopy and laser physics. It is well known that the first laser in the history is a ruby laser activated with Cr(3+). It was found in early nineties that Cr(4+) was also an interesting lasing ion in the near infrared, and various Cr(4+) lasers have been developed. Very recently, it was reported that Cr(2+) doped in CdSe crystals showed lasing action in the infrared. The above achievement have stimulated an interest in searching for Cr(5+) and investigating its optical properties. Cr(5+) is isoelectronic with Ti(3+) and V(4+), having electron configuration 3d1. Ti(3+) is the active center of commercial cw and femtosecond sapphire lasers, tunable in the range 680-1100 nm. V(4+) doped in YAlO3 and Al2O3 showed broad band emission near 635 nm. Although EPR results of Cr(5+) were reported, the optical properties were less studied. Herren et al. reported an observation of luminescence from Cr doped in SiO2 sol-gel glass. The luminescence spectrum was assigned to pentavalent ions in their first paper, and later it was identified to be the emission from the charge transfer transition of Cr(6+). The first observation of photoluminescence from octahedrally coordinated Cr(5+) in BaCaMg aluminate glasses was reported very recently. In this work, we report luminescence results of Cr doped SiO2 sol-gel glasses. The fluorescence spectra are very different from Herrens' results, and we believe it originates from pentavalent Cr.

Jia, Weiyi↗
NASA NTRS2019

Schedule Factors Associated with the Use of Controlled Rest in a Long-Haul Airline

Controlled Rest (CR) refers to a short, voluntary nap opportunity taken by pilots on the flight deck as a countermeasure to unanticipated sleepiness in flight. This study explores the profile of CR use in a long-haul commercial airline. Forty-four pilots wore actiwatches and filled in an application-based sleep/work diary for approximately 2 weeks. After merging sleep diary, actigraphy, and schedule data, complete records were analyzed from 240 flights. Sleep was estimated during CR intervals using the Philips Actiware 6.0.9 (Bend, OR) software with wake threshold set to medium. Timing of sleep periods and flight schedules were analyzed relative to home-base time. A mixed-effects binary logistics regression was used to analyze the impact of schedule factors on CR. Preliminary analyses revealed that CR was taken on 45% (n=107) of flights. Average sleep duration within these rest periods was estimated as 24.8 ± 16.1 minutes. CR was more frequent on return flights (arriving at home-base; 58%, n=69) vs. outbound flights (departing from home-base, 31%, n=38; p<0.001). There was no difference for direction of travel (eastbound: 49%, n= 56; westbound: 40%, n= 44; northbound/southbound: 50%, n=7; p=0.272). CR was more frequent on 2-pilot flights (62%, n=81) compared to augmented crew flights (24%, n=26; p<0.001). Of note, 21% (n=23) of augmented flights contained both CR and Bunk Rest. CR was more frequent on flights <10h duration (<10h: 59%, n=78; >10h: 27%, n=29; p<0.001). Flights departing between 12:00h-19:59h (25%, n=23; p<0.026) had the lowest frequency of CR. Data from this airline show that CR is most commonly used as a countermeasure to sleepiness on return, unaugmented, <10h duration, and nighttime flights. The direction of travel did not influence the use of CR. Future studies are required to determine generalizability of these results to other airlines.

Hilditch, Cassie↗
NASA NTRSDate not supplied

Pink Spinel in Apollo Impact Melt Rock 68815: Implications for Mg-Suite Magmatism

Introduction: Magnesian rocks from the lunar highlands are collectively termed the Mg-suite. Characterized by high (>60) Mg# (molar 100×Mg/[Mg+Fe]) in mafic phases and calcic plagioclase, these rocks are plutonic to hypabyssal in origin, and include a range of bulk mineralogies such as troctolites, dunites, norites, gabbronorites, and spinel troctolites [1]. These Mg-suite lithologies have distinct trace element concentrations and ratios that differentiate them from other lunar rock types. These rocks are ancient, generally dated to between 4.5 and 4.1 Ga, although it is unknown if this represents the full range of Mg-suite ages [1–2]. Among the Mg-suite lithologies, the spinel troctolites are relatively rare, to date only found in polymict breccias [3]. Spinel troctolites, as their name suggests, consist of calcic plagioclase and forsteritic olivine, with minor amounts of spinel (MgAl2O4), ± pyroxene and cordierite [1,4]. This form of spinel is often called ‘pink’ spinel because of its appearance in thin section under plane polarized light (PPL; Fig. 1), due to minor amounts of Cr. Spinel troctolites are generally plutonic or hypabyssal in origin (subsequently exhumed and incorporated into polymict breccias), or formed through impact processes (e.g., crystalline impact melt) [5]. A spinel-rich lithology has also been found in the Moscoviense region of the Moon via the Moon Mineralogy Mapper (M3) and lacks other mafic phases [6]. Finally, while the Mg-suite sampled thus far consists of plutonic (or hypabyssal) rocks, the question remains if such magmas could have erupted on the surface of the Moon [7]. These magmas have much lower density than mare basalts, but little sample or remote sensing evidence has been found to support the idea that extrusive Mg-suite volcanism occurred [7]. Here, we present a coordinated microanalytical study of spinel-bearing lithic and mineral clasts found in Apollo sample 68815. These data will be used to understand their petrogenesis (magmatic or impact) and modification histories, and to shed light on the existence of volcanic Mg-suite rocks. Sample Description: Apollo sample 68815 is a polymict impact melt breccia containing a variety of lithic and mineral fragments embedded in devitrified impact melt. This sample was chipped off the top of a boulder at Station 8 during the Apollo 16 mission and had an original weight of nearly 1.8 kg. In this study, we investigated two polished thin sections of 68815: 68815,17 and 68815,148, both containing spinel. Methods: The thin sections of 68815 were studied using optical light microscopy (PPL, cross-polarized light, and reflected light) with a Keyence VHX-7100 Digital Microscope. Each section was then X-ray mapped for 13–14 elements using a Cameca SX100 electron probe microanalyzer (EPMA) located in the Kuiper Materials Imaging and Characterization Facility (KMICF) at the University of Arizona. We have obtained geochemical information about the phases (olivine, plagioclase, spinel, pyroxene) in the thin sections also using the EPMA. In addition, we have used ThermoScientific Helios NanoLab 660 Focused-Ion-Beam Scanning-Electron Microscope (FIB-SEM) and a Hitachi S-4800 SEM (both in KMICF) to obtain backscattered electron (BSE) images and energy dispersive Xray spectrometry (EDS) maps of areas of interest. Using a JEOL 7900F SEM at the Astromaterials Research & Exploration Science (ARES) at NASA Johnson Space Center (JSC), we have obtained electron backscatter diffraction (EBSD) maps of the spinel-bearing portions of the thin sections. The EBSD data were collected under beam conditions of 20 kV, and ~90 μA, with step sizes varying from 0.05 to 2 μm. Following EBSD data collection, we processed the data using AZtecCrystal and MTEX, a free MATLAB toolbox. Results: We have found clasts with subophitic textures, that consist of primarily olivine and plagioclase, with minor amounts of pink Mg-Al spinel and pyroxene (Fig. 1). These clasts are up to ~1 mm in length and contain spinels up to 50 μm across. We have additionally identified pink Mg-Al spinels within the impact melt (i.e., not contained in lithic clasts) in both thin sections. In one instance, a single spinel grain is approximately 300 μm across (Fig. 1b, 2). The spinel fragments embedded in impact melt have varying compositions, typically distinct from the compositions of spinels in the lithic clasts. Spinel-Bearing Clasts: Ten lithic clasts with similar textures and mineral compositions were identified between 68815,17 (two clasts) and ,148 (eight clasts). These clasts fall into two groups. The first has skeletal olivine with intergranular plagioclase, with minor amounts of pyroxene and spinel (Fig. 1a, 2c, 2d). The spinel in these clasts are found amid the plagioclase. The second group have an intergranular texture of olivine and plagioclase, again with minor spinel and pyroxene. The second group may contain spinels surrounded by plagioclase, and spinels enclosed in olivine. Spinels located within both clast types range from no apparent Cr zoning, to reverse zoning (Cr-enrichment inward; Fig. 2d), to normal zoning (Cr-enrichment outward). In the clasts thus far investigated with EPMA, plagioclase compositions range from An# (molar 100×Ca/[Ca+Na+K]) 92–96. Olivine Mg# ranged from 77 to 94, while pyroxene had Mg# from 54–84. Spinel in the clasts have Cr# (molar 100×Cr/[Cr+Al]) 2–4 and Mg# 88–91, which is within the range of pristine and plutonic spinel troctolites [8]. Isolated Spinels: These crystals are generally euhedral to subhedral, and can exhibit reverse Cr zoning (Cr enrichment inward) or no apparent Cr zoning. The spinels thus far investigated via EPMA have Cr# 9–14 and Mg# 65–82. The Cr# for these spinels is within the range reported by [8], but have lower Mg#. Future Work: We will continue to process the EBSD data for these lithic and mineral clasts. We will also continue to characterize these clasts using EPMA and SEM. By thoroughly characterizing the various spinels and spinel-bearing clasts, we aim to constrain the petrogenesis of these minerals and rock fragments. Acknowledgments: We thank NASA for the loan of these thin sections. We thank Ken Domanik and Jerry Chang for their support with data collection. Work was supported by a University of Arizona RII Core Facilities Pilot Program grant and start-up funds to JJB. We acknowledge support from NASA’s Planetary Science Research program for analysis performed at JSC. References: [1] Shearer C. K. et al. (2015) Am. Min. 100, 294–325. [2] Borg L. E. et al. (2020) GCA 290, 312–332. [3] Warren P. H. (1993) Am. Min. 78, 360–376. [4] Dymek R. F. et al. (1976) LPS VII, 2335–2378. [5] Treiman et al. (2019) Am. Min. 104, 370–384. [6] Pieters et al. (2011) JGR: Plan. 116:E00G08. [7] Prissel et al. (2016) Icarus 277, 319–329. [8] Prissel et al. (2016) Am. Min. 101, 1624–1635.

spinel↗
DOE OSTI2020

Materials Data on Nb3Cr3C by Materials Project

Nb3Cr3C crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Nb is bonded in a distorted bent 150 degrees geometry to six Cr and two equivalent C atoms. There are two shorter (2.82 Å) and four longer (2.94 Å) Nb–Cr bond lengths. Both Nb–C bond lengths are 2.19 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded to six equivalent Nb and six Cr atoms to form distorted CrNb6Cr6 cuboctahedra that share corners with nine CrNb6Cr6 cuboctahedra, corners with three equivalent CNb6 octahedra, faces with thirteen CrNb6Cr6 cuboctahedra, and faces with three equivalent CNb6 octahedra. The corner-sharing octahedral tilt angles are 43°. There are three shorter (2.47 Å) and three longer (2.57 Å) Cr–Cr bond lengths. 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 six equivalent CrNb6Cr6 cuboctahedra, edges with six equivalent CNb6 octahedra, and faces with fourteen CrNb6Cr6 cuboctahedra. C is bonded to six equivalent Nb atoms to form CNb6 octahedra that share corners with six equivalent CrNb6Cr6 cuboctahedra, corners with six equivalent CNb6 octahedra, edges with six equivalent CrNb6Cr6 cuboctahedra, and faces with six equivalent CrNb6Cr6 cuboctahedra. The corner-sharing octahedral tilt angles are 42°.

36 MATERIALS SCIENCE↗