Materials Data on CaWO2 by Materials Project

Abstract

CaWO2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are two shorter (2.31 Å) and three longer (2.32 Å) Ca–O bond lengths. In the second Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.33 Å. In the third Ca2+ site, Ca2+ is bonded to five O2- atoms to form a mixture of distorted corner and edge-sharing CaO5 square pyramids. There are a spread of Ca–O bond distances ranging from 2.21–2.54 Å. In the fourth Ca2+ site, Ca2+ is bonded to five O2- atoms to form a mixture of distorted corner and edge-sharing CaO5 square pyramids. There are a spread of Ca–O bond distances ranging from 2.22–2.53 Å. There are four inequivalent W2+ sites. In the first W2+ site, W2+ is bonded in a distorted pentagonal planar geometry to five O2- atoms. There are a spread of W–O bond distances ranging from 2.18–2.28 Å. In the second W2+ site, W2+ is bonded in a distorted pentagonal planar geometry to five O2- atoms. There are a spread of W–O bond distances ranging from 2.09–2.31 Å. In the third W2+ site, W2+ is bonded in a distorted pentagonal planar geometry to five O2- atoms. There are a spread of W–O bond distances ranging from 2.08–2.32 Å. In the fourth W2+ site, W2+ is bonded in a distorted pentagonal planar geometry to five O2- atoms. There are a spread of W–O bond distances ranging from 2.17–2.29 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W2+ atoms. In the second O2- site, O2- is bonded to three Ca2+ and three W2+ atoms to form OCa3W3 octahedra that share corners with four OCa3W2 trigonal bipyramids, edges with four OCa3W3 octahedra, and a faceface with one OCa3W2 trigonal bipyramid. In the third O2- site, O2- is bonded to three Ca2+ and three W2+ atoms to form OCa3W3 octahedra that share corners with four OCa3W2 trigonal bipyramids, edges with four OCa3W3 octahedra, and a faceface with one OCa3W2 trigonal bipyramid. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W2+ atoms. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two equivalent W2+ atoms. In the sixth O2- site, O2- is bonded to three Ca2+ and two equivalent W2+ atoms to form distorted OCa3W2 trigonal bipyramids that share corners with four OCa3W3 octahedra, edges with two equivalent OCa3W2 trigonal bipyramids, and a faceface with one OCa3W3 octahedra. The corner-sharing octahedra tilt angles range from 45–55°. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two equivalent W2+ atoms. In the eighth O2- site, O2- is bonded to three Ca2+ and two equivalent W2+ atoms to form distorted OCa3W2 trigonal bipyramids that share corners with four OCa3W3 octahedra, edges with two equivalent OCa3W2 trigonal bipyramids, and a faceface with one OCa3W3 octahedra. The corner-sharing octahedra tilt angles range from 44–55°.