cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.17188/1694636
title: Materials Data on Cr6Co2CuSe12 by Materials Project

description: Cr6Co2CuSe12 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with two equivalent CuSe6 octahedra, corners with four equivalent CoSe6 octahedra, edges with six CrSe6 octahedra, and a faceface with one CoSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There are a spread of Cr–Se bond distances ranging from 2.48–2.62 Å. In the second Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with six equivalent CoSe6 octahedra, edges with six CrSe6 octahedra, and a faceface with one CoSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–52°. There are a spread of Cr–Se bond distances ranging from 2.50–2.62 Å. In the third Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with two equivalent CoSe6 octahedra, corners with four equivalent CuSe6 octahedra, edges with six CrSe6 octahedra, and a faceface with one CuSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There are a spread of Cr–Se bond distances ranging from 2.51–2.56 Å. Co2+ is bonded to six Se2- atoms to form CoSe6 octahedra that share corners with twelve CrSe6 octahedra, edges with two equivalent CoSe6 octahedra, and faces with two CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–53°. There are a spread of Co–Se bond distances ranging from 2.47–2.52 Å. Cu2+ is bonded to six Se2- atoms to form CuSe6 octahedra that share corners with twelve CrSe6 octahedra, edges with two equivalent CuSe6 octahedra, and faces with two equivalent CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There are two shorter (2.54 Å) and four longer (2.59 Å) Cu–Se bond lengths. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to three Cr3+ and two equivalent Co2+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to three Cr3+ and two equivalent Co2+ atoms. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent Cr3+ and two equivalent Cu2+ atoms. In the fourth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Cr3+ and one Cu2+ atom. In the fifth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to three equivalent Cr3+ and one Co2+ atom. In the sixth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to three Cr3+ and one Co2+ atom.
DOI: 10.17188/1694637
title: Materials Data on LaTiNbO6 by Materials Project

description: LaNbTiO6 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.45–2.76 Å. In the second La3+ site, La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.43–2.76 Å. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share edges with three equivalent NbO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.89–2.05 Å. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share edges with three equivalent TiO6 octahedra. There are a spread of Nb–O bond distances ranging from 1.94–2.10 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two La3+, one Ti4+, and one Nb5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two La3+, one Ti4+, and one Nb5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one La3+, one Ti4+, and one Nb5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one La3+, one Ti4+, and one Nb5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one La3+, one Ti4+, and one Nb5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one La3+, one Ti4+, and one Nb5+ atom.
DOI: 10.17188/1694638
title: Materials Data on Ho(PPd)2 by Materials Project

description: Ho(PdP)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho is bonded in a 8-coordinate geometry to eight equivalent Pd and eight equivalent P atoms. All Ho–Pd bond lengths are 3.21 Å. All Ho–P bond lengths are 3.09 Å. Pd is bonded to four equivalent Ho, four equivalent Pd, and four equivalent P atoms to form a mixture of distorted edge, corner, and face-sharing PdHo4P4Pd4 cuboctahedra. All Pd–Pd bond lengths are 2.89 Å. All Pd–P bond lengths are 2.47 Å. P is bonded in a 9-coordinate geometry to four equivalent Ho, four equivalent Pd, and one P atom. The P–P bond length is 2.19 Å.
DOI: 10.17188/1694639
title: Materials Data on Na3TlI6 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1694640
title: Materials Data on TiSiO4 by Materials Project

description: TiSiO4 is Zircon structured and crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. Ti4+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (1.99 Å) and four longer (2.24 Å) Ti–O bond lengths. Si4+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Si–O bond lengths are 1.63 Å. O2- is bonded in a 2-coordinate geometry to two equivalent Ti4+ and one Si4+ atom.
DOI: 10.17188/1694641
title: Materials Data on GeSe2 by Materials Project

description: GeSe2 crystallizes in the orthorhombic Fdd2 space group. The structure is three-dimensional. there are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four Se2- atoms to form corner-sharing GeSe4 tetrahedra. All Ge–Se bond lengths are 2.41 Å. In the second Ge4+ site, Ge4+ is bonded to four Se2- atoms to form corner-sharing GeSe4 tetrahedra. There are a spread of Ge–Se bond distances ranging from 2.39–2.41 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a water-like geometry to two equivalent Ge4+ atoms. In the second Se2- site, Se2- is bonded in a water-like geometry to two Ge4+ atoms. In the third Se2- site, Se2- is bonded in a water-like geometry to two Ge4+ atoms.
DOI: 10.17188/1694642
title: Materials Data on Sc2CrN3 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1694643
title: Materials Data on Zr4BN3 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1694644
title: Materials Data on CaNdAlO4 by Materials Project

description: CaNdAlO4 is (La,Ba)CuO4-derived structured and crystallizes in the tetragonal I4mm space group. The structure is three-dimensional. Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.64 Å. Nd3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Nd–O bond distances ranging from 2.35–2.64 Å. Al3+ is bonded to six O2- atoms to form corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 9°. There are a spread of Al–O bond distances ranging from 1.86–2.17 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+, four equivalent Nd3+, and one Al3+ atom to form distorted OCaNd4Al octahedra that share corners with seventeen OCa2Nd2Al2 octahedra, edges with eight OCaNd4Al octahedra, and faces with four equivalent OCa2Nd2Al2 octahedra. The corner-sharing octahedra tilt angles range from 0–53°. In the second O2- site, O2- is bonded to four equivalent Ca2+, one Nd3+, and one Al3+ atom to form distorted OCa4NdAl octahedra that share corners with seventeen OCa2Nd2Al2 octahedra, edges with eight OCaNd4Al octahedra, and faces with four equivalent OCa2Nd2Al2 octahedra. The corner-sharing octahedra tilt angles range from 0–55°. In the third O2- site, O2- is bonded to two equivalent Ca2+, two equivalent Nd3+, and two equivalent Al3+ atoms to form a mixture of distorted edge, face, and corner-sharing OCa2Nd2Al2 octahedra. The corner-sharing octahedra tilt angles range from 9–55°.
DOI: 10.17188/1694645
title: Materials Data on Y2AlRu by Materials Project

description: Y2RuAl is Heusler structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Y is bonded in a body-centered cubic geometry to four equivalent Ru and four equivalent Al atoms. All Y–Ru bond lengths are 3.04 Å. All Y–Al bond lengths are 3.04 Å. Ru is bonded in a body-centered cubic geometry to eight equivalent Y atoms. Al is bonded in a body-centered cubic geometry to eight equivalent Y atoms.
DOI: 10.17188/1694646
title: Materials Data on Li3V5O12 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1694647
title: Materials Data on Ta4CrSe8 by Materials Project

description: Ta4CrSe8 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ta+3.50+ sites. In the first Ta+3.50+ site, Ta+3.50+ is bonded to six equivalent Se2- atoms to form distorted TaSe6 pentagonal pyramids that share edges with six equivalent TaSe6 pentagonal pyramids and faces with two equivalent CrSe6 octahedra. All Ta–Se bond lengths are 2.60 Å. In the second Ta+3.50+ site, Ta+3.50+ is bonded to six Se2- atoms to form distorted TaSe6 pentagonal pyramids that share corners with four equivalent CrSe6 octahedra and edges with six TaSe6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 47°. There are two shorter (2.58 Å) and four longer (2.63 Å) Ta–Se bond lengths. Cr2+ is bonded to six equivalent Se2- atoms to form CrSe6 octahedra that share corners with twelve equivalent TaSe6 pentagonal pyramids and faces with two equivalent TaSe6 pentagonal pyramids. All Cr–Se bond lengths are 2.48 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to three equivalent Ta+3.50+ atoms. In the second Se2- site, Se2- is bonded to three Ta+3.50+ and one Cr2+ atom to form a mixture of distorted face, edge, and corner-sharing SeTa3Cr trigonal pyramids.
DOI: 10.17188/1694648
title: Materials Data on SrO6 by Materials Project

description: SrO6 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Sr is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of Sr–O bond distances ranging from 2.50–2.94 Å. There are three inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to one Sr and one O atom. The O–O bond length is 1.29 Å. In the second O site, O is bonded in a trigonal non-coplanar geometry to two equivalent Sr and one O atom. In the third O site, O is bonded in a 3-coordinate geometry to two equivalent Sr and one O atom. The O–O bond length is 1.35 Å.
DOI: 10.17188/1694650
title: Materials Data on Fe3Co2Cu(PO4)6 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1694651
title: Materials Data on Mg3Si2O9 by Materials Project

description: Mg3Si2O9 crystallizes in the monoclinic Cc space group. The structure is two-dimensional and consists of two Mg3Si2O9 sheets oriented in the (0, 0, 1) direction. there are three inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two SiO4 tetrahedra and edges with six MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.12 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two SiO4 tetrahedra and edges with six MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.11 Å. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two SiO4 tetrahedra and edges with six MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.12 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. All Si–O bond lengths are 1.65 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–56°. All Si–O bond lengths are 1.65 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a trigonal non-coplanar geometry to three Mg atoms. In the second O site, O is bonded in a trigonal non-coplanar geometry to three Mg atoms. In the third O site, O is bonded in a trigonal non-coplanar geometry to three Mg atoms. In the fourth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the sixth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the seventh O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom. In the eighth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom. In the ninth O site, O is bonded in a trigonal non-coplanar geometry to three Mg atoms.
DOI: 10.17188/1694652
title: Materials Data on YTl(WO4)2 by Materials Project

description: YTl(WO4)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Y3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Y–O bond distances ranging from 2.29–2.33 Å. W6+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles are 42°. There are a spread of W–O bond distances ranging from 1.83–2.12 Å. Tl1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Tl–O bond distances ranging from 2.89–3.13 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent W6+ and two equivalent Tl1+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Y3+, one W6+, and one Tl1+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Y3+, two equivalent W6+, and one Tl1+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Y3+, one W6+, and one Tl1+ atom.
DOI: 10.17188/1694653
title: Materials Data on K2AlTlI6 by Materials Project

description: K2TlAlI6 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. K1+ is bonded to twelve equivalent I1- atoms to form distorted KI12 cuboctahedra that share corners with twelve equivalent KI12 cuboctahedra, faces with six equivalent KI12 cuboctahedra, faces with four equivalent TlI6 octahedra, and faces with four equivalent AlI6 octahedra. All K–I bond lengths are 4.32 Å. Tl1+ is bonded to six equivalent I1- atoms to form TlI6 octahedra that share corners with six equivalent AlI6 octahedra and faces with eight equivalent KI12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Tl–I bond lengths are 3.32 Å. Al3+ is bonded to six equivalent I1- atoms to form AlI6 octahedra that share corners with six equivalent TlI6 octahedra and faces with eight equivalent KI12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Al–I bond lengths are 2.78 Å. I1- is bonded in a distorted linear geometry to four equivalent K1+, one Tl1+, and one Al3+ atom.
DOI: 10.17188/1694654
title: Materials Data on NaCo2H3(SO5)2 by Materials Project

description: NaCo2H3(SO5)2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Na1+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.42–2.75 Å. Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with four SO4 tetrahedra and edges with two equivalent CoO6 octahedra. There are a spread of Co–O bond distances ranging from 2.02–2.22 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.14 Å) and one longer (1.28 Å) H–O bond length. There are two inequivalent S6+ sites. In the first S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with four equivalent CoO6 octahedra. The corner-sharing octahedra tilt angles range from 48–51°. There are a spread of S–O bond distances ranging from 1.46–1.53 Å. In the second S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with four equivalent CoO6 octahedra. The corner-sharing octahedra tilt angles range from 48–51°. There are a spread of S–O bond distances ranging from 1.46–1.53 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and one S6+ atom. In the second O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and one S6+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Co2+, and one S6+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Co2+, and one S6+ atom. In the fifth O2- site, O2- is bonded to two equivalent Co2+ and two H1+ atoms to form distorted corner-sharing OCo2H2 tetrahedra. In the sixth O2- site, O2- is bonded to two equivalent Co2+ and two H1+ atoms to form distorted corner-sharing OCo2H2 tetrahedra. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two equivalent Co2+, and one S6+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two equivalent Co2+, and one S6+ atom.
DOI: 10.17188/1694655
title: Materials Data on TeO3 by Materials Project

description: TeO3 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are two inequivalent Te6+ sites. In the first Te6+ site, Te6+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing TeO6 octahedra. The corner-sharing octahedra tilt angles range from 37–43°. There are a spread of Te–O bond distances ranging from 1.92–2.02 Å. In the second Te6+ site, Te6+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing TeO6 octahedra. The corner-sharing octahedra tilt angles range from 37–47°. There are a spread of Te–O bond distances ranging from 1.94–1.99 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two Te6+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Te6+ atoms. In the third O2- site, O2- is bonded in a water-like geometry to two Te6+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Te6+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Te6+ atoms. In the sixth O2- site, O2- is bonded in a water-like geometry to two Te6+ atoms.
DOI: 10.17188/1694657
title: Materials Data on CeTl5Ni2(NO2)12 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1694659
title: Materials Data on KDy3F10 by Materials Project

description: KDy3F10 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. K1+ is bonded to sixteen F1- atoms to form distorted edge-sharing KF16 tetrahedra. There are four shorter (2.78 Å) and twelve longer (3.23 Å) K–F bond lengths. Dy3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are four shorter (2.22 Å) and four longer (2.38 Å) Dy–F bond lengths. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent K1+ and two equivalent Dy3+ atoms. In the second F1- site, F1- is bonded to one K1+ and three equivalent Dy3+ atoms to form a mixture of edge and corner-sharing FKDy3 tetrahedra.
DOI: 10.17188/1694660
title: Materials Data on LaCBr by Materials Project

description: LaCBr crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one LaCBr sheet oriented in the (0, 0, 1) direction. La3+ is bonded in a 8-coordinate geometry to five equivalent C2- and three equivalent Br1- atoms. There are a spread of La–C bond distances ranging from 2.51–2.84 Å. There are two shorter (3.07 Å) and one longer (3.18 Å) La–Br bond lengths. C2- is bonded in a 2-coordinate geometry to five equivalent La3+ and one C2- atom. The C–C bond length is 1.32 Å. Br1- is bonded in a 3-coordinate geometry to three equivalent La3+ atoms.
DOI: 10.17188/1694661
title: Materials Data on GaCoRh2 by Materials Project

description: Rh2CoGa crystallizes in the orthorhombic Immm space group. The structure is one-dimensional and consists of two Rh2CoGa ribbons oriented in the (1, 0, 0) direction. Rh is bonded in a linear geometry to one Co and one Ga atom. The Rh–Co bond length is 2.22 Å. The Rh–Ga bond length is 2.38 Å. Co is bonded in a linear geometry to two equivalent Rh atoms. Ga is bonded in a linear geometry to two equivalent Rh atoms.
DOI: 10.17188/1694662
title: Materials Data on Ca(FeAs)2 by Materials Project

description: CaFe2As2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ca2+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All Ca–As bond lengths are 3.17 Å. Fe2+ is bonded to four equivalent As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.31 Å. As3- is bonded in a 9-coordinate geometry to four equivalent Ca2+ and four equivalent Fe2+ atoms.