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Materials Data on Cr3NiP4 by Materials Project

Cr3NiP4 is Modderite-derived structured and 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 P3- atoms to form distorted CrP6 pentagonal pyramids that share corners with four equivalent NiP6 octahedra, corners with eight equivalent CrP6 octahedra, edges with four equivalent CrP6 octahedra, edges with two equivalent CrP6 pentagonal pyramids, and faces with two equivalent NiP6 octahedra. The corner-sharing octahedra tilt angles range from 42–59°. There are a spread of Cr–P bond distances ranging from 2.27–2.40 Å. In the second Cr+3.33+ site, Cr+3.33+ is bonded to six P3- atoms to form distorted CrP6 octahedra that share corners with four equivalent CrP6 octahedra, corners with eight equivalent CrP6 pentagonal pyramids, edges with two equivalent CrP6 octahedra, edges with four equivalent NiP6 octahedra, and faces with two equivalent CrP6 octahedra. The corner-sharing octahedra tilt angles range from 56–60°. There are a spread of Cr–P bond distances ranging from 2.31–2.41 Å. In the third Cr+3.33+ site, Cr+3.33+ is bonded to six P3- atoms to form distorted CrP6 octahedra that share corners with four equivalent CrP6 octahedra, corners with eight equivalent NiP6 octahedra, edges with two equivalent CrP6 octahedra, edges with four equivalent CrP6 pentagonal pyramids, and faces with two equivalent CrP6 octahedra. The corner-sharing octahedra tilt angles range from 42–60°. There are a spread of Cr–P bond distances ranging from 2.30–2.40 Å. Ni2+ is bonded to six P3- atoms to form distorted NiP6 octahedra that share corners with eight equivalent CrP6 octahedra, corners with four equivalent CrP6 pentagonal pyramids, edges with two equivalent NiP6 octahedra, edges with four equivalent CrP6 octahedra, and faces with two equivalent CrP6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 42–55°. There are a spread of Ni–P bond distances ranging from 2.31–2.41 Å. There are four inequivalent P3- sites. In the first P3- site, P3- is bonded in a 6-coordinate geometry to five Cr+3.33+ and one Ni2+ atom. In the second P3- site, P3- is bonded in a 6-coordinate geometry to five Cr+3.33+ and one Ni2+ atom. In the third P3- site, P3- is bonded in a 6-coordinate geometry to four Cr+3.33+ and two equivalent Ni2+ atoms. In the fourth P3- site, P3- is bonded in a 6-coordinate geometry to four Cr+3.33+ and two equivalent Ni2+ atoms.

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Materials Data on Yb6Al43Cr4 by Materials Project

Yb6Cr4Al43 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. Yb is bonded in a 6-coordinate geometry to one Yb, one Cr, and fifteen Al atoms. The Yb–Yb bond length is 3.39 Å. The Yb–Cr bond length is 3.51 Å. There are a spread of Yb–Al bond distances ranging from 3.06–3.44 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a cuboctahedral geometry to twelve Al atoms. There are six shorter (2.65 Å) and six longer (2.78 Å) Cr–Al bond lengths. In the second Cr site, Cr is bonded in a 10-coordinate geometry to two equivalent Yb and ten Al atoms. There are a spread of Cr–Al bond distances ranging from 2.54–2.67 Å. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to two equivalent Yb, one Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.75–2.94 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to two equivalent Yb, one Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.71–3.11 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to four equivalent Yb and eight Al atoms. There are two shorter (2.78 Å) and two longer (2.84 Å) Al–Al bond lengths. In the fourth Al site, Al is bonded in a 2-coordinate geometry to two equivalent Cr and ten Al atoms. There are two shorter (2.78 Å) and four longer (2.89 Å) Al–Al bond lengths. In the fifth Al site, Al is bonded in a 10-coordinate geometry to two equivalent Yb, one Cr, and seven Al atoms. There are one shorter (2.74 Å) and two longer (2.82 Å) Al–Al bond lengths. In the sixth Al site, Al is bonded in a 12-coordinate geometry to one Yb, two Cr, and nine Al atoms. Both Al–Al bond lengths are 2.95 Å. In the seventh Al site, Al is bonded to three equivalent Yb and nine Al atoms to form a mixture of face and corner-sharing AlYb3Al9 cuboctahedra.

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Materials Data on Mn3Cr3P2 by Materials Project

Cr3Mn3P2 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are three inequivalent Cr sites. In the first Cr site, Cr is bonded in a 2-coordinate geometry to two P atoms. There are one shorter (2.35 Å) and one longer (2.38 Å) Cr–P bond lengths. In the second Cr site, Cr is bonded in a 2-coordinate geometry to one Mn and two P atoms. The Cr–Mn bond length is 2.44 Å. Both Cr–P bond lengths are 2.36 Å. In the third Cr site, Cr is bonded in a 3-coordinate geometry to three P atoms. There are a spread of Cr–P bond distances ranging from 2.31–2.41 Å. There are three inequivalent Mn sites. In the first Mn site, Mn is bonded in a 4-coordinate geometry to one Cr and three P atoms. There are a spread of Mn–P bond distances ranging from 2.26–2.34 Å. In the second Mn site, Mn is bonded in a 4-coordinate geometry to four P atoms. There are a spread of Mn–P bond distances ranging from 2.25–2.34 Å. In the third Mn site, Mn is bonded in a 4-coordinate geometry to four P atoms. There are a spread of Mn–P bond distances ranging from 2.25–2.32 Å. There are two inequivalent P sites. In the first P site, P is bonded in a 9-coordinate geometry to four Cr and five Mn atoms. In the second P site, P is bonded in a 9-coordinate geometry to three Cr and six Mn atoms.

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Materials Data on Sm6Al43Cr4 by Materials Project

Sm6Cr4Al43 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. Sm is bonded in a 6-coordinate geometry to one Sm, one Cr, and fifteen Al atoms. The Sm–Sm bond length is 3.44 Å. The Sm–Cr bond length is 3.54 Å. There are a spread of Sm–Al bond distances ranging from 3.06–3.49 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a 10-coordinate geometry to two equivalent Sm and ten Al atoms. There are a spread of Cr–Al bond distances ranging from 2.53–2.67 Å. In the second Cr site, Cr is bonded in a cuboctahedral geometry to twelve Al atoms. There are six shorter (2.66 Å) and six longer (2.79 Å) Cr–Al bond lengths. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to one Sm, two Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.72–2.95 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to four equivalent Sm and eight Al atoms. There are a spread of Al–Al bond distances ranging from 2.76–3.13 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to two equivalent Sm, one Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.75–3.02 Å. In the fourth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Cr and ten Al atoms. Both Al–Al bond lengths are 2.76 Å. In the fifth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Sm, one Cr, and nine Al atoms. Both Al–Al bond lengths are 2.95 Å. In the sixth Al site, Al is bonded to three equivalent Sm and nine Al atoms to form a mixture of face and corner-sharing AlSm3Al9 cuboctahedra. All Al–Al bond lengths are 2.82 Å. In the seventh Al site, Al is bonded in a 10-coordinate geometry to two equivalent Sm, one Cr, and seven Al atoms. The Al–Al bond length is 2.75 Å.

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Materials Data on U6Al43Cr4 by Materials Project

U6Cr4Al43 is Hexagonal Laves-derived structured and crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. U is bonded in a 2-coordinate geometry to one U, one Cr, and fifteen Al atoms. The U–U bond length is 3.02 Å. The U–Cr bond length is 3.65 Å. There are a spread of U–Al bond distances ranging from 3.00–3.52 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a distorted q6 geometry to two equivalent U and ten Al atoms. There are a spread of Cr–Al bond distances ranging from 2.52–2.64 Å. In the second Cr site, Cr is bonded to twelve Al atoms to form CrAl12 cuboctahedra that share faces with six equivalent AlU2Al9Cr cuboctahedra. There are six shorter (2.63 Å) and six longer (2.79 Å) Cr–Al bond lengths. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to one U, two Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.68–2.98 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to four equivalent U and eight Al atoms. There are a spread of Al–Al bond distances ranging from 2.71–3.03 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to two equivalent U, one Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.69–3.05 Å. In the fourth Al site, Al is bonded in a 2-coordinate geometry to two equivalent Cr and ten Al atoms. Both Al–Al bond lengths are 2.78 Å. In the fifth Al site, Al is bonded to two equivalent U, one Cr, and nine Al atoms to form distorted AlU2Al9Cr cuboctahedra that share a cornercorner with one AlU2Al9Cr cuboctahedra, edges with three AlU2Al9Cr cuboctahedra, a faceface with one CrAl12 cuboctahedra, and faces with six AlU2Al9Cr cuboctahedra. Both Al–Al bond lengths are 2.92 Å. In the sixth Al site, Al is bonded to three equivalent U and nine Al atoms to form AlU3Al9 cuboctahedra that share corners with three equivalent AlU3Al9 cuboctahedra, edges with three equivalent AlU2Al9Cr cuboctahedra, and faces with five AlU2Al9Cr cuboctahedra. All Al–Al bond lengths are 2.80 Å. In the seventh Al site, Al is bonded in a 10-coordinate geometry to two equivalent U, one Cr, and seven Al atoms. The Al–Al bond length is 2.64 Å.

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Materials Data on CaNd3Cr4O16 by Materials Project

CaNd3Cr4O16 is Zircon-derived structured and crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.42 Å) and four longer (2.55 Å) Ca–O bond lengths. There are two inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.43 Å) and four longer (2.51 Å) Nd–O bond lengths. In the second Nd3+ site, Nd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Nd–O bond distances ranging from 2.42–2.50 Å. There are three inequivalent Cr+5.25+ sites. In the first Cr+5.25+ site, Cr+5.25+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.72 Å) and two longer (1.74 Å) Cr–O bond length. In the second Cr+5.25+ site, Cr+5.25+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Cr–O bond lengths are 1.72 Å. In the third Cr+5.25+ site, Cr+5.25+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Cr–O bond lengths are 1.66 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two Nd3+ and one Cr+5.25+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, one Nd3+, and one Cr+5.25+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two Nd3+ and one Cr+5.25+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, one Nd3+, and one Cr+5.25+ atom.

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Materials Data on Cr3Pt by Materials Project

Cr3Pt is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a 12-coordinate geometry to eight Cr and four equivalent Pt atoms. There are a spread of Cr–Cr bond distances ranging from 2.43–2.93 Å. There are two shorter (2.67 Å) and two longer (2.69 Å) Cr–Pt bond lengths. In the second Cr site, Cr is bonded in a 12-coordinate geometry to eight Cr and four equivalent Pt atoms. Both Cr–Cr bond lengths are 2.49 Å. There are two shorter (2.67 Å) and two longer (2.69 Å) Cr–Pt bond lengths. Pt is bonded to twelve Cr atoms to form a mixture of corner and face-sharing PtCr12 cuboctahedra.

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Materials Data on Er6Al43Cr4 by Materials Project

Er6Cr4Al43 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. Er is bonded in a 6-coordinate geometry to one Er, one Cr, and fifteen Al atoms. The Er–Er bond length is 3.38 Å. The Er–Cr bond length is 3.46 Å. There are a spread of Er–Al bond distances ranging from 3.02–3.44 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a 12-coordinate geometry to two equivalent Er and ten Al atoms. There are a spread of Cr–Al bond distances ranging from 2.55–2.65 Å. In the second Cr site, Cr is bonded to twelve Al atoms to form CrAl12 cuboctahedra that share edges with six equivalent AlAl10Cr2 cuboctahedra. There are six shorter (2.63 Å) and six longer (2.79 Å) Cr–Al bond lengths. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to one Er, two Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.69–2.92 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to four equivalent Er and eight Al atoms. There are a spread of Al–Al bond distances ranging from 2.71–3.06 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to two equivalent Er, one Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.71–3.00 Å. In the fourth Al site, Al is bonded to two equivalent Cr and ten Al atoms to form distorted AlAl10Cr2 cuboctahedra that share corners with four equivalent AlEr3Al9 cuboctahedra, edges with two equivalent CrAl12 cuboctahedra, and faces with two equivalent AlAl10Cr2 cuboctahedra. Both Al–Al bond lengths are 2.74 Å. In the fifth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Er, one Cr, and nine Al atoms. Both Al–Al bond lengths are 2.94 Å. In the sixth Al site, Al is bonded to three equivalent Er and nine Al atoms to form a mixture of face and corner-sharing AlEr3Al9 cuboctahedra. All Al–Al bond lengths are 2.79 Å. In the seventh Al site, Al is bonded in a 10-coordinate geometry to two equivalent Er, one Cr, and seven Al atoms. The Al–Al bond length is 2.72 Å.

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Materials Data on Y6Al43Cr4 by Materials Project

Y6Cr4Al43 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. Y is bonded in a 6-coordinate geometry to one Y, one Cr, and fifteen Al atoms. The Y–Y bond length is 3.39 Å. The Y–Cr bond length is 3.49 Å. There are a spread of Y–Al bond distances ranging from 3.03–3.48 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a 10-coordinate geometry to two equivalent Y and ten Al atoms. There are a spread of Cr–Al bond distances ranging from 2.55–2.65 Å. In the second Cr site, Cr is bonded to twelve Al atoms to form CrAl12 cuboctahedra that share edges with six equivalent AlAl10Cr2 cuboctahedra. There are six shorter (2.64 Å) and six longer (2.78 Å) Cr–Al bond lengths. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to one Y, two Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.70–2.92 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to four equivalent Y and eight Al atoms. There are a spread of Al–Al bond distances ranging from 2.73–3.08 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to two equivalent Y, one Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.72–3.00 Å. In the fourth Al site, Al is bonded to two equivalent Cr and ten Al atoms to form distorted AlAl10Cr2 cuboctahedra that share corners with four equivalent AlY3Al9 cuboctahedra, edges with two equivalent CrAl12 cuboctahedra, and faces with two equivalent AlAl10Cr2 cuboctahedra. Both Al–Al bond lengths are 2.74 Å. In the fifth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Y, one Cr, and nine Al atoms. Both Al–Al bond lengths are 2.93 Å. In the sixth Al site, Al is bonded to three equivalent Y and nine Al atoms to form a mixture of face and corner-sharing AlY3Al9 cuboctahedra. All Al–Al bond lengths are 2.80 Å. In the seventh Al site, Al is bonded in a 10-coordinate geometry to two equivalent Y, one Cr, and seven Al atoms. The Al–Al bond length is 2.73 Å.

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Materials Data on Cr5NiS8 by Materials Project

Cr5NiS8 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. there are three inequivalent Cr+2.80+ sites. In the first Cr+2.80+ site, Cr+2.80+ is bonded to six S2- atoms to form CrS6 octahedra that share corners with two equivalent NiS6 octahedra, corners with four equivalent CrS6 octahedra, edges with six CrS6 octahedra, and a faceface with one NiS6 octahedra. The corner-sharing octahedra tilt angles range from 47–52°. There are a spread of Cr–S bond distances ranging from 2.37–2.45 Å. In the second Cr+2.80+ site, Cr+2.80+ is bonded to six S2- atoms to form CrS6 octahedra that share corners with two equivalent CrS6 octahedra, corners with four equivalent NiS6 octahedra, edges with six CrS6 octahedra, and a faceface with one CrS6 octahedra. The corner-sharing octahedra tilt angles range from 47–53°. There are a spread of Cr–S bond distances ranging from 2.33–2.51 Å. In the third Cr+2.80+ site, Cr+2.80+ is bonded to six S2- atoms to form a mixture of edge, corner, and face-sharing CrS6 octahedra. The corner-sharing octahedra tilt angles range from 47–52°. There are two shorter (2.39 Å) and four longer (2.41 Å) Cr–S bond lengths. Ni2+ is bonded to six S2- atoms to form NiS6 octahedra that share corners with twelve CrS6 octahedra, edges with two equivalent NiS6 octahedra, and faces with two equivalent CrS6 octahedra. The corner-sharing octahedra tilt angles range from 47–53°. There are two shorter (2.36 Å) and four longer (2.42 Å) Ni–S bond lengths. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Cr+2.80+ atoms. In the second S2- site, S2- is bonded in a rectangular see-saw-like geometry to three Cr+2.80+ and one Ni2+ atom. In the third S2- site, S2- is bonded to five Cr+2.80+ atoms to form a mixture of distorted edge and corner-sharing SCr5 trigonal bipyramids. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to three Cr+2.80+ and two equivalent Ni2+ atoms.

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Materials Data on Cr5NiAs3 by Materials Project

Cr5NiAs3 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are three inequivalent Cr sites. In the first Cr site, Cr is bonded in a 5-coordinate geometry to two equivalent Ni and five As atoms. Both Cr–Ni bond lengths are 2.83 Å. There are one shorter (2.61 Å) and four longer (2.67 Å) Cr–As bond lengths. In the second Cr site, Cr is bonded in a 5-coordinate geometry to five As atoms. There are one shorter (2.58 Å) and four longer (2.64 Å) Cr–As bond lengths. In the third Cr site, Cr is bonded in a 4-coordinate geometry to four As atoms. There are a spread of Cr–As bond distances ranging from 2.43–2.47 Å. Ni is bonded in a 4-coordinate geometry to two equivalent Cr and four As atoms. There are two shorter (2.37 Å) and two longer (2.38 Å) Ni–As bond lengths. There are two inequivalent As sites. In the first As site, As is bonded in a 9-coordinate geometry to eight Cr and one Ni atom. In the second As site, As is bonded in a 9-coordinate geometry to seven Cr and two equivalent Ni atoms.

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Materials Data on Cr4B by Materials Project

Cr4B crystallizes in the orthorhombic F222 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 two equivalent B atoms. Both Cr–B bond lengths are 2.14 Å. In the second Cr site, Cr is bonded in a distorted bent 150 degrees geometry to two equivalent B atoms. Both Cr–B bond lengths are 2.18 Å. In the third Cr site, Cr is bonded in a distorted water-like geometry to two equivalent B atoms. Both Cr–B bond lengths are 2.17 Å. In the fourth Cr site, Cr is bonded in a 2-coordinate geometry to two equivalent B atoms. Both Cr–B bond lengths are 2.17 Å. B is bonded in a 8-coordinate geometry to eight Cr atoms.

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Materials Data on Cr5NiS8 by Materials Project

Cr5NiS8 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent Cr+2.80+ sites. In the first Cr+2.80+ site, Cr+2.80+ is bonded to six S2- atoms to form CrS6 octahedra that share corners with two equivalent CrS6 octahedra, corners with four equivalent NiS6 octahedra, edges with six CrS6 octahedra, and a faceface with one CrS6 octahedra. The corner-sharing octahedra tilt angles range from 48–53°. There are a spread of Cr–S bond distances ranging from 2.33–2.47 Å. In the second Cr+2.80+ site, Cr+2.80+ is bonded to six S2- atoms to form CrS6 octahedra that share corners with two equivalent NiS6 octahedra, corners with four equivalent CrS6 octahedra, edges with six CrS6 octahedra, and a faceface with one NiS6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Cr–S bond distances ranging from 2.32–2.49 Å. In the third Cr+2.80+ site, Cr+2.80+ is bonded to six S2- atoms to form CrS6 octahedra that share corners with twelve CrS6 octahedra, edges with two equivalent NiS6 octahedra, and faces with two equivalent CrS6 octahedra. The corner-sharing octahedra tilt angles range from 48–54°. There are a spread of Cr–S bond distances ranging from 2.40–2.44 Å. Ni2+ is bonded to six S2- atoms to form NiS6 octahedra that share corners with twelve CrS6 octahedra, edges with two equivalent CrS6 octahedra, and faces with two equivalent CrS6 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There are a spread of Ni–S bond distances ranging from 2.38–2.42 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to three Cr+2.80+ and one Ni2+ atom. In the second S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Cr+2.80+ atoms. In the third S2- site, S2- is bonded to four Cr+2.80+ and one Ni2+ atom to form a mixture of distorted edge and corner-sharing SCr4Ni trigonal bipyramids. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to four Cr+2.80+ and one Ni2+ atom.

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Materials Data on Zr2Cr2F3 by Materials Project

Zr2Cr2F3 crystallizes in the monoclinic Cm space group. The structure is two-dimensional and consists of one Zr2Cr2F3 sheet oriented in the (2, 0, -1) direction. there are three inequivalent Zr sites. In the first Zr site, Zr is bonded in a bent 120 degrees geometry to two F atoms. There are one shorter (2.11 Å) and one longer (2.12 Å) Zr–F bond lengths. In the second Zr site, Zr is bonded in a 2-coordinate geometry to three F atoms. There are a spread of Zr–F bond distances ranging from 2.16–2.48 Å. In the third Zr site, Zr is bonded in a 3-coordinate geometry to two equivalent F atoms. Both Zr–F bond lengths are 2.45 Å. There are three inequivalent Cr sites. In the first Cr site, Cr is bonded in a linear geometry to two F atoms. Both Cr–F bond lengths are 2.02 Å. In the second Cr site, Cr is bonded in a single-bond geometry to one F atom. The Cr–F bond length is 2.11 Å. In the third Cr site, Cr is bonded in a 2-coordinate geometry to three F atoms. There are two shorter (2.38 Å) and one longer (2.62 Å) Cr–F bond lengths. There are four inequivalent F sites. In the first F site, F is bonded in a 4-coordinate geometry to three Zr and one Cr atom. In the second F site, F is bonded in a distorted trigonal planar geometry to one Zr and two Cr atoms. In the third F site, F is bonded in a distorted trigonal non-coplanar geometry to two Zr and one Cr atom. In the fourth F site, F is bonded in a bent 120 degrees geometry to one Zr and one Cr atom.

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Materials Data on V2(CrSi)3 by Materials Project

V2(CrSi)3 crystallizes in the orthorhombic Ibam space group. The structure is three-dimensional. V2+ is bonded in a 7-coordinate geometry to one Cr+2.67+ and six Si4- atoms. The V–Cr bond length is 2.55 Å. There are a spread of V–Si bond distances ranging from 2.44–2.65 Å. There are two inequivalent Cr+2.67+ sites. In the first Cr+2.67+ site, Cr+2.67+ is bonded in a 7-coordinate geometry to one V2+ and six Si4- atoms. There are a spread of Cr–Si bond distances ranging from 2.42–2.66 Å. In the second Cr+2.67+ site, Cr+2.67+ is bonded in a distorted hexagonal planar geometry to two equivalent Cr+2.67+ and four equivalent Si4- atoms. Both Cr–Cr bond lengths are 2.33 Å. All Cr–Si bond lengths are 2.44 Å. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 10-coordinate geometry to four equivalent V2+, four equivalent Cr+2.67+, and two equivalent Si4- atoms. Both Si–Si bond lengths are 2.33 Å. In the second Si4- site, Si4- is bonded in a 10-coordinate geometry to four equivalent V2+ and six Cr+2.67+ atoms.

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DOE OSTI2020

Materials Data on Tb6Al43Cr4 by Materials Project

Tb6Cr4Al43 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. Tb is bonded in a 6-coordinate geometry to one Tb, one Cr, and fifteen Al atoms. The Tb–Tb bond length is 3.41 Å. The Tb–Cr bond length is 3.50 Å. There are a spread of Tb–Al bond distances ranging from 3.04–3.48 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a 12-coordinate geometry to two equivalent Tb and ten Al atoms. There are a spread of Cr–Al bond distances ranging from 2.56–2.67 Å. In the second Cr site, Cr is bonded to twelve Al atoms to form CrAl12 cuboctahedra that share edges with six equivalent AlAl10Cr2 cuboctahedra. There are six shorter (2.64 Å) and six longer (2.81 Å) Cr–Al bond lengths. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to one Tb, two Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.71–2.93 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to four equivalent Tb and eight Al atoms. There are a spread of Al–Al bond distances ranging from 2.74–3.09 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to two equivalent Tb, one Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.73–3.03 Å. In the fourth Al site, Al is bonded to two equivalent Cr and ten Al atoms to form distorted AlAl10Cr2 cuboctahedra that share corners with four equivalent AlTb3Al9 cuboctahedra, edges with two equivalent CrAl12 cuboctahedra, and faces with two equivalent AlAl10Cr2 cuboctahedra. Both Al–Al bond lengths are 2.75 Å. In the fifth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Tb, one Cr, and nine Al atoms. Both Al–Al bond lengths are 2.96 Å. In the sixth Al site, Al is bonded to three equivalent Tb and nine Al atoms to form a mixture of face and corner-sharing AlTb3Al9 cuboctahedra. All Al–Al bond lengths are 2.81 Å. In the seventh Al site, Al is bonded in a 10-coordinate geometry to two equivalent Tb, one Cr, and seven Al atoms. The Al–Al bond length is 2.75 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Elucidation of puzzling questions regarding the CrO x /Al 2 O 3 catalyst I. X-ray absorption spectroscopy aided identification of the nature of the chromium oxide species in the CrO x /Al 2 O 3 dehydrogenation catalyst system

The CATOFIN© process produces propylene from propane using a CrO x /Al 2 O 3 catalyst. Despite its use, there are still uncertainties surrounding the nature of Cr species formed during synthesis, regeneration, and aging. It has been observed that ppm levels of Cr 2 O 3 can be oxidized to Cr(VI) in air; however, when Cr 2 O 3 is in direct contact with Al 2 O 3 , Cr(VI) formation increased more than 100-fold. Here, to confirm physical contact between Cr 2 O 3 and Al 2 O 3 results in increased Cr(VI) formation, Cr 2 O 3 and Cr 2 O 3 /Al 2 O 3 samples were synthesized, calcined, and characterized. Catalytic activity measurements confirm propylene selectivity inversely tracks with Cr(VI). Wet chemical titration and X-ray absorption spectroscopy (XAS) quantified and determined the structure of the Cr(VI) species. FEFF X-ray absorption near edge structure simulations determined the potential sensitivity of the XAS to the presence of Al 3+ /Cr 3+ neighboring atoms. XAS correlated to FEFF simulations suggested that Al 3+ x Cr 3+ 2–x Cr 6+ 3 O 12 comprises a significant fraction of the Cr(VI) species formed.

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

Alkali-activated slag (AAS) and OPC-based composites containing crumb rubber aggregate: Physico-mechanical properties, durability and oxidation of rubber upon NaOH treatment

Value-added utilization of waste tires in cementitious materials has been studied for decades, whereas the synergy between rubber and alkali-activated cements deserves more investigations. To this end, we compared physico-mechanical and durability properties of alkali-activated slag (AAS) and OPC-based composites containing NaOH-pretreated/as-received crumb rubber (CR). It was found that the incorporation of CR had both positive and negative effects on specimens due to its special attributes. CR reduced electrical conductivity which was associated with the ion transport ability, since it worked as an electrical insulator and increased hydrophobicity of pore walls. The sulfate expansion decreased with CR content because the flow of sulfate ions was demobilized, and the flexibility of CR relieved the internal stress. CR also improved the freeze-thaw durability of composites if the total CR content was less than 30% in specimens. However, the low Young's modulus of CR impaired the compressive strength and failed to effectively control the total shrinkage upon drying. The composites with CR must avoid high temperature exposure which resulted in the pyrolysis of rubber. In addition, the NaOH pretreatment enhanced adhesion between CR and hydrated cement and improved overall performances of composites. The FTIR spectra confirmed the NaOH-induced accelerated oxidation of CR surface and the generation of polar functional groups including carbonyl and carboxyl groups, increasing the total surface energy of rubber. More importantly, the alkali-activation process for AAS could treat the CR aggregate in the meantime, which means the use of CR in alkali-activated cements does not require the pretreatment of CR before blending.

36 MATERIALS SCIENCE↗