DOI: 10.17188/1317882
title: Materials Data on Ca(WO2)2 by Materials Project

description: Ca(WO2)2 is Spinel-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with three equivalent CaO6 octahedra and corners with nine WO6 octahedra. The corner-sharing octahedra tilt angles range from 52–70°. There are a spread of Ca–O bond distances ranging from 2.27–2.33 Å. In the second Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with three equivalent CaO6 octahedra and corners with nine WO6 octahedra. The corner-sharing octahedra tilt angles range from 53–68°. There are a spread of Ca–O bond distances ranging from 2.23–2.34 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with three equivalent CaO4 tetrahedra and edges with six WO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.27–2.40 Å. In the fourth Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with twelve WO6 octahedra. The corner-sharing octahedra tilt angles range from 53–65°. There are a spread of Ca–O bond distances ranging from 2.25–2.39 Å. In the fifth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with three equivalent CaO4 tetrahedra, corners with three equivalent WO4 trigonal pyramids, and edges with six WO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.33–2.41 Å. In the sixth Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with twelve WO6 octahedra. The corner-sharing octahedra tilt angles range from 58–62°. There are a spread of Ca–O bond distances ranging from 2.26–2.33 Å. There are twelve inequivalent W3+ sites. In the first W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with three CaO4 tetrahedra, a cornercorner with one WO4 trigonal pyramid, edges with two CaO6 octahedra, and edges with four WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.30 Å. In the second W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with three CaO4 tetrahedra, a cornercorner with one WO4 trigonal pyramid, edges with two CaO6 octahedra, and edges with four WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.27 Å. In the third W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with five CaO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.29 Å. In the fourth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with three CaO4 tetrahedra, a cornercorner with one WO4 trigonal pyramid, edges with two CaO6 octahedra, and edges with four WO6 octahedra. There are a spread of W–O bond distances ranging from 2.02–2.21 Å. In the fifth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with five CaO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.16–2.25 Å. In the sixth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six CaO4 tetrahedra and edges with six WO6 octahedra. There are a spread of W–O bond distances ranging from 2.16–2.24 Å. In the seventh W3+ site, W3+ is bonded in a distorted trigonal planar geometry to three O2- atoms. There are a spread of W–O bond distances ranging from 2.04–2.29 Å. In the eighth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with four CaO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.23 Å. In the ninth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with five CaO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.05–2.19 Å. In the tenth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with four CaO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.26 Å. In the eleventh W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with four CaO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.22 Å. In the twelfth W3+ site, W3+ is bonded to four O2- atoms to form distorted WO4 trigonal pyramids that share corners with three equivalent CaO6 octahedra and corners with nine WO6 octahedra. The corner-sharing octahedra tilt angles range from 42–75°. There are a spread of W–O bond distances ranging from 2.03–2.60 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share a cornercorner with one OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the second O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form a mixture of distorted edge and corner-sharing OCaW3 tetrahedra. In the third O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share a cornercorner with one OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the fourth O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share a cornercorner with one OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the fifth O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share corners with five OCaW3 tetrahedra, corners with four OW4 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the seventh O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 tetrahedra that share corners with nine OCaW3 tetrahedra, corners with three equivalent OW4 trigonal pyramids, and edges with three OCa2W2 trigonal pyramids. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two W3+ atoms. In the ninth O2- site, O2- is bonded to four W3+ atoms to form distorted OW4 trigonal pyramids that share corners with three equivalent OCaW3 tetrahedra and corners with six OCa2W2 trigonal pyramids. In the tenth O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share corners with five OCaW3 tetrahedra, corners with four OW4 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the eleventh O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share corners with five OCaW3 tetrahedra, corners with four OW4 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the twelfth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the thirteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form a mixture of distorted edge and corner-sharing OCaW3 tetrahedra. In the fourteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 tetrahedra that share corners with eight OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, edges with two OCaW3 tetrahedra, and an edgeedge with one OW4 trigonal pyramid. In the fifteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 tetrahedra that share corners with eight OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, edges with two OCaW3 tetrahedra, and an edgeedge with one OW4 trigonal pyramid. In the sixteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 tetrahedra that share corners with three equivalent OCaW3 tetrahedra, corners with three OCa2W2 trigonal pyramids, and edges with three OCaW3 tetrahedra. In the seventeenth O2- site, O2- is bonded to four W3+ atoms to form distorted OW4 trigonal pyramids that share corners with three equivalent OCaW3 tetrahedra, corners with six OCa2W2 trigonal pyramids, and edges with three OCaW3 tetrahedra. In the eighteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form a mixture of distorted edge and corner-sharing OCaW3 tetrahedra. In the nineteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form a mixture of distorted edge and corner-sharing OCaW3 tetrahedra. In the twentieth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 tetrahedra that share corners with eight OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, edges with two OCaW3 tetrahedra, and an edgeedge with one OW4 trigonal pyramid. In the twenty-first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the twenty-second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the twenty-third O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted corner-sharing OCaW3 tetrahedra. In the twenty-fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms.