cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.17188/1716186
title: Materials Data on Ba3PrIrRuO9 by Materials Project

description: Ba3PrRuIrO9 is (Cubic) Perovskite-derived structured and crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with twelve BaO12 cuboctahedra, faces with six BaO12 cuboctahedra, faces with two equivalent PrO6 octahedra, faces with three equivalent RuO6 octahedra, and faces with three equivalent IrO6 octahedra. There are a spread of Ba–O bond distances ranging from 3.02–3.04 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, corners with three equivalent IrO6 octahedra, faces with seven BaO12 cuboctahedra, a faceface with one IrO6 octahedra, faces with three equivalent PrO6 octahedra, and faces with three equivalent RuO6 octahedra. The corner-sharing octahedral tilt angles are 13°. There are a spread of Ba–O bond distances ranging from 2.91–3.27 Å. In the third Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, corners with three equivalent RuO6 octahedra, faces with seven BaO12 cuboctahedra, a faceface with one RuO6 octahedra, faces with three equivalent PrO6 octahedra, and faces with three equivalent IrO6 octahedra. The corner-sharing octahedral tilt angles are 13°. There are a spread of Ba–O bond distances ranging from 2.92–3.31 Å. Pr3+ is bonded to six O2- atoms to form PrO6 octahedra that share corners with three equivalent RuO6 octahedra, corners with three equivalent IrO6 octahedra, and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are three shorter (2.30 Å) and three longer (2.34 Å) Pr–O bond lengths. Ru5+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent PrO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one IrO6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are three shorter (1.95 Å) and three longer (2.06 Å) Ru–O bond lengths. Ir4+ is bonded to six O2- atoms to form IrO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent PrO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one RuO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (1.98 Å) and three longer (2.06 Å) Ir–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+, one Ru5+, and one Ir4+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to four Ba2+, one Pr3+, and one Ru5+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to four Ba2+, one Pr3+, and one Ir4+ atom.
DOI: 10.17188/1716187
title: Materials Data on Ta3Mo3N4 by Materials Project

description: Ta3Mo3N4 crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. there are three inequivalent Ta sites. In the first Ta site, Ta is bonded to five N atoms to form a mixture of distorted edge and corner-sharing TaN5 square pyramids. There are four shorter (2.19 Å) and one longer (2.27 Å) Ta–N bond lengths. In the second Ta site, Ta is bonded to five N atoms to form distorted TaN5 square pyramids that share corners with four equivalent TaN5 square pyramids, edges with four equivalent TaN5 square pyramids, and edges with four equivalent MoN5 square pyramids. There are four shorter (2.19 Å) and one longer (2.26 Å) Ta–N bond lengths. In the third Ta site, Ta is bonded to five N atoms to form a mixture of distorted edge and corner-sharing TaN5 square pyramids. There are four shorter (2.18 Å) and one longer (2.23 Å) Ta–N bond lengths. There are three inequivalent Mo sites. In the first Mo site, Mo is bonded in a linear geometry to two N atoms. There are one shorter (2.16 Å) and one longer (2.26 Å) Mo–N bond lengths. In the second Mo site, Mo is bonded in a distorted linear geometry to two N atoms. Both Mo–N bond lengths are 2.24 Å. In the third Mo site, Mo is bonded to five N atoms to form MoN5 square pyramids that share corners with four equivalent MoN5 square pyramids, edges with four equivalent TaN5 square pyramids, and edges with four equivalent MoN5 square pyramids. There are four shorter (2.18 Å) and one longer (2.23 Å) Mo–N bond lengths. There are four inequivalent N sites. In the first N site, N is bonded to four equivalent Ta and two Mo atoms to form distorted NTa4Mo2 octahedra that share corners with five NTa5Mo octahedra and edges with eight NTaMo5 octahedra. The corner-sharing octahedra tilt angles range from 0–20°. In the second N site, N is bonded to five Ta and one Mo atom to form NTa5Mo octahedra that share corners with five NTaMo5 octahedra and edges with eight NTa5Mo octahedra. The corner-sharing octahedra tilt angles range from 0–18°. In the third N site, N is bonded to one Ta and five Mo atoms to form a mixture of edge and corner-sharing NTaMo5 octahedra. The corner-sharing octahedra tilt angles range from 0–18°. In the fourth N site, N is bonded to five Ta and one Mo atom to form a mixture of distorted edge and corner-sharing NTa5Mo octahedra. The corner-sharing octahedra tilt angles range from 0–20°.
DOI: 10.17188/1716188
title: Materials Data on KTmP2O7 by Materials Project

description: KTmP2O7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.90–3.57 Å. Tm3+ is bonded to six O2- atoms to form TmO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Tm–O bond distances ranging from 2.17–2.26 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent TmO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 17–51°. There is three shorter (1.53 Å) and one longer (1.64 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent TmO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 15–48°. There are a spread of P–O bond distances ranging from 1.51–1.63 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to one K1+, one Tm3+, and one P5+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one K1+ and two P5+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Tm3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+, one Tm3+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Tm3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Tm3+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted linear geometry to one K1+, one Tm3+, and one P5+ atom.
DOI: 10.17188/1716189
title: Materials Data on ScAgSn by Materials Project

description: ScAgSn crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Sc is bonded in a 7-coordinate geometry to six equivalent Ag and five Sn atoms. There are two shorter (3.17 Å) and four longer (3.51 Å) Sc–Ag bond lengths. There are four shorter (3.05 Å) and one longer (3.15 Å) Sc–Sn bond lengths. Ag is bonded to six equivalent Sc, two equivalent Ag, and four Sn atoms to form a mixture of distorted face, edge, and corner-sharing AgSc6Ag2Sn4 cuboctahedra. Both Ag–Ag bond lengths are 3.05 Å. There are two shorter (2.77 Å) and two longer (2.81 Å) Ag–Sn bond lengths. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded in a 9-coordinate geometry to three equivalent Sc and six equivalent Ag atoms. In the second Sn site, Sn is bonded in a 9-coordinate geometry to six equivalent Sc and three equivalent Ag atoms.
DOI: 10.17188/1716190
title: Materials Data on Li2Mo4O13 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: 10.17188/1716191
title: Materials Data on Sr3Sc2N4 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: 10.17188/1716192
title: Materials Data on CaLaVFeO6 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: 10.17188/1716193
title: Materials Data on ErNiGe by Materials Project

description: ErNiGe crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Er is bonded in a 12-coordinate geometry to six equivalent Ni and six equivalent Ge atoms. There are a spread of Er–Ni bond distances ranging from 2.93–3.22 Å. There are a spread of Er–Ge bond distances ranging from 2.97–3.15 Å. Ni is bonded in a 10-coordinate geometry to six equivalent Er, one Ni, and three equivalent Ge atoms. The Ni–Ni bond length is 2.65 Å. There are two shorter (2.40 Å) and one longer (2.63 Å) Ni–Ge bond lengths. Ge is bonded in a 10-coordinate geometry to six equivalent Er, three equivalent Ni, and one Ge atom. The Ge–Ge bond length is 2.72 Å.
DOI: 10.17188/1716194
title: Materials Data on LiYSi by Materials Project

description: LiYSi is half-Heusler structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional and consists of four lithium molecules and one YSi framework. In the YSi framework, Y3+ is bonded to four equivalent Si4- atoms to form corner-sharing YSi4 tetrahedra. All Y–Si bond lengths are 2.88 Å. Si4- is bonded to four equivalent Y3+ atoms to form corner-sharing SiY4 tetrahedra.
DOI: 10.17188/1716195
title: Materials Data on CaPb3Se4 by Materials Project

description: CaPb3Se4 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. Ca2+ is bonded to six Se2- atoms to form CaSe6 octahedra that share corners with six equivalent PbSe6 octahedra, edges with two equivalent CaSe6 octahedra, and edges with ten PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. All Ca–Se bond lengths are 3.03 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to six Se2- atoms to form PbSe6 octahedra that share corners with six equivalent PbSe6 octahedra, edges with four equivalent CaSe6 octahedra, and edges with eight PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 2–3°. All Pb–Se bond lengths are 3.09 Å. In the second Pb2+ site, Pb2+ is bonded to six Se2- atoms to form PbSe6 octahedra that share corners with six equivalent CaSe6 octahedra, edges with two equivalent CaSe6 octahedra, and edges with ten PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. All Pb–Se bond lengths are 3.15 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to one Ca2+ and five Pb2+ atoms to form a mixture of edge and corner-sharing SeCaPb5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second Se2- site, Se2- is bonded to two equivalent Ca2+ and four Pb2+ atoms to form SeCa2Pb4 octahedra that share corners with six equivalent SeCa2Pb4 octahedra and edges with twelve SeCaPb5 octahedra. The corner-sharing octahedral tilt angles are 0°.
DOI: 10.17188/1716196
title: Materials Data on U(Zn10Rh)2 by Materials Project

description: U(RhZn10)2 crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. U is bonded in a 4-coordinate geometry to sixteen Zn atoms. There are four shorter (3.09 Å) and twelve longer (3.11 Å) U–Zn bond lengths. Rh is bonded to twelve Zn atoms to form RhZn12 cuboctahedra that share corners with six equivalent RhZn12 cuboctahedra, edges with eighteen equivalent ZnUZn10Rh cuboctahedra, and faces with six equivalent ZnUZn10Rh cuboctahedra. There are six shorter (2.53 Å) and six longer (2.80 Å) Rh–Zn bond lengths. There are three inequivalent Zn sites. In the first Zn site, Zn is bonded in a 2-coordinate geometry to two equivalent U and twelve equivalent Zn atoms. All Zn–Zn bond lengths are 3.03 Å. In the second Zn site, Zn is bonded in a distorted linear geometry to two equivalent Rh and six equivalent Zn atoms. There are two shorter (2.69 Å) and four longer (2.83 Å) Zn–Zn bond lengths. In the third Zn site, Zn is bonded to one U, one Rh, and ten Zn atoms to form distorted ZnUZn10Rh cuboctahedra that share corners with fifteen equivalent ZnUZn10Rh cuboctahedra, edges with two equivalent ZnUZn10Rh cuboctahedra, edges with three equivalent RhZn12 cuboctahedra, a faceface with one RhZn12 cuboctahedra, and faces with fifteen equivalent ZnUZn10Rh cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.62–2.92 Å.
DOI: 10.17188/1716197
title: Materials Data on NaFeP3H7O13 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: 10.17188/1716198
title: Materials Data on GaN 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: 10.17188/1716199
title: Materials Data on Mg2Ta2FeO8 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: 10.17188/1716200
title: Materials Data on HfTa by Materials Project

description: HfTa crystallizes in the orthorhombic Cmmm space group. The structure is two-dimensional and consists of two HfTa sheets oriented in the (0, 1, 0) direction. Hf is bonded in a 8-coordinate geometry to four equivalent Ta atoms. All Hf–Ta bond lengths are 2.97 Å. Ta is bonded in a 8-coordinate geometry to four equivalent Hf atoms.
DOI: 10.17188/1716201
title: Materials Data on ZnSeO5 by Materials Project

description: (ZnSeO4)2O2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional and consists of two hydrogen peroxide molecules and one ZnSeO4 framework. In the ZnSeO4 framework, Zn is bonded to four O atoms to form ZnO4 tetrahedra that share corners with four equivalent SeO4 tetrahedra and an edgeedge with one ZnO4 tetrahedra. There are a spread of Zn–O bond distances ranging from 1.94–2.07 Å. Se is bonded to four O atoms to form SeO4 tetrahedra that share corners with four equivalent ZnO4 tetrahedra. There are a spread of Se–O bond distances ranging from 1.63–1.75 Å. There are four inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one Zn and one Se atom. In the second O site, O is bonded in a trigonal planar geometry to two equivalent Zn and one Se atom. In the third O site, O is bonded in a bent 120 degrees geometry to one Zn and one Se atom. In the fourth O site, O is bonded in a single-bond geometry to one Se atom.
DOI: 10.17188/1716203
title: Materials Data on Zr3Sb by Materials Project

description: Zr3Sb crystallizes in the tetragonal I-4 space group. The structure is three-dimensional. there are three inequivalent Zr sites. In the first Zr site, Zr is bonded in a distorted water-like geometry to two equivalent Sb atoms. There are one shorter (2.93 Å) and one longer (3.06 Å) Zr–Sb bond lengths. In the second Zr site, Zr is bonded in a 3-coordinate geometry to three equivalent Sb atoms. There are a spread of Zr–Sb bond distances ranging from 2.91–3.11 Å. In the third Zr site, Zr is bonded in a 4-coordinate geometry to four equivalent Sb atoms. There are a spread of Zr–Sb bond distances ranging from 2.95–2.98 Å. Sb is bonded in a 9-coordinate geometry to nine Zr atoms.
DOI: 10.17188/1716206
title: Materials Data on ScTiCo2 by Materials Project

description: ScTiCo2 crystallizes in the orthorhombic Immm space group. The structure is one-dimensional and consists of two ScTiCo2 ribbons oriented in the (1, 0, 0) direction. Sc is bonded in a linear geometry to two equivalent Co atoms. Both Sc–Co bond lengths are 2.34 Å. Ti is bonded in a linear geometry to two equivalent Co atoms. Both Ti–Co bond lengths are 2.05 Å. Co is bonded in a linear geometry to one Sc and one Ti atom.
DOI: 10.17188/1716207
title: Materials Data on AuCl by Materials Project

description: AuCl crystallizes in the tetragonal P4_2/ncm space group. The structure is one-dimensional and consists of two AuCl ribbons oriented in the (1, 1, 0) direction. Au1+ is bonded in a linear geometry to two equivalent Cl1- atoms. Both Au–Cl bond lengths are 2.35 Å. Cl1- is bonded in an L-shaped geometry to two equivalent Au1+ atoms.
DOI: 10.17188/1716208
title: Materials Data on TiNF 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: 10.17188/1716209
title: Materials Data on LiMn2O4 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: 10.17188/1716210
title: Materials Data on Eu4Bi3 by Materials Project

description: Eu4Bi3 crystallizes in the cubic I-43d space group. The structure is three-dimensional. Eu is bonded to six equivalent Bi atoms to form a mixture of distorted edge, face, and corner-sharing EuBi6 octahedra. The corner-sharing octahedra tilt angles range from 18–49°. There are three shorter (3.35 Å) and three longer (3.56 Å) Eu–Bi bond lengths. Bi is bonded to eight equivalent Eu atoms to form a mixture of distorted edge, face, and corner-sharing BiEu8 hexagonal bipyramids.
DOI: 10.17188/1716212
title: Materials Data on Li2Ca(MnN)2 by Materials Project

description: Li2Ca(MnN)2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Li is bonded in a trigonal planar geometry to three equivalent N atoms. There are one shorter (2.07 Å) and two longer (2.10 Å) Li–N bond lengths. Ca is bonded in a square co-planar geometry to four equivalent N atoms. All Ca–N bond lengths are 2.60 Å. Mn is bonded in a linear geometry to two equivalent N atoms. Both Mn–N bond lengths are 1.87 Å. N is bonded to three equivalent Li, two equivalent Ca, and two equivalent Mn atoms to form a mixture of distorted edge and corner-sharing NLi3Ca2Mn2 pentagonal bipyramids.
DOI: 10.17188/1716214
title: Materials Data on HfCrAgS4 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: 10.17188/1716215
title: Materials Data on Ba2La3Ti2Nb2O15 by Materials Project

description: Ba2La3Ti2Nb2O15 crystallizes in the trigonal P-3c1 space group. The structure is three-dimensional. Ba2+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of Ba–O bond distances ranging from 2.72–3.32 Å. There are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are six shorter (2.53 Å) and three longer (3.00 Å) La–O bond lengths. In the second La3+ site, La3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are three shorter (2.52 Å) and six longer (2.71 Å) La–O bond lengths. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with three equivalent TiO6 octahedra and corners with three equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 19–21°. There are three shorter (2.00 Å) and three longer (2.02 Å) Ti–O bond lengths. Nb+4.50+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with three equivalent TiO6 octahedra. The corner-sharing octahedral tilt angles are 21°. There are three shorter (1.91 Å) and three longer (2.16 Å) Nb–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+, two La3+, one Ti4+, and one Nb+4.50+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to three La3+ and two equivalent Ti4+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three equivalent Ba2+, one La3+, and one Nb+4.50+ atom.
DOI: 10.17188/1716216
title: Materials Data on CrB2Ru by Materials Project

description: CrRuB2 crystallizes in the orthorhombic Pmc2_1 space group. The structure is three-dimensional. Cr3+ is bonded in a 7-coordinate geometry to seven B3- atoms. There are a spread of Cr–B bond distances ranging from 2.20–2.43 Å. Ru3+ is bonded in a 7-coordinate geometry to seven B3- atoms. There are a spread of Ru–B bond distances ranging from 2.25–2.33 Å. There are two inequivalent B3- sites. In the first B3- site, B3- is bonded in a 9-coordinate geometry to three equivalent Cr3+, four equivalent Ru3+, and two equivalent B3- atoms. Both B–B bond lengths are 1.77 Å. In the second B3- site, B3- is bonded in a 9-coordinate geometry to four equivalent Cr3+, three equivalent Ru3+, and two equivalent B3- atoms.
DOI: 10.17188/1716217
title: Materials Data on Ca5P3O13 by Materials Project

description: Ca5P3O13 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of Ca–O bond distances ranging from 2.42–2.86 Å. In the second Ca site, Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.36–2.81 Å. P is bonded in a tetrahedral geometry to four O atoms. There is three shorter (1.55 Å) and one longer (1.56 Å) P–O bond length. There are four inequivalent O sites. In the first O site, O is bonded in a trigonal planar geometry to three equivalent Ca atoms. In the second O site, O is bonded in a 1-coordinate geometry to three Ca and one P atom. In the third O site, O is bonded to three Ca and one P atom to form distorted edge-sharing OCa3P tetrahedra. In the fourth O site, O is bonded in a 1-coordinate geometry to three Ca and one P atom.