Materials Data on CaV2O4 by Materials Project

Abstract

CaV2O4 crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 pentagonal pyramids that share corners with six equivalent VO6 octahedra and edges with six VO6 octahedra. The corner-sharing octahedra tilt angles range from 6–17°. There are two shorter (2.35 Å) and four longer (2.43 Å) Ca–O bond lengths. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are two shorter (2.37 Å) and four longer (2.43 Å) Ca–O bond lengths. There are two inequivalent V3+ sites. In the first V3+ site, V3+ is bonded to six O2- atoms to form VO6 octahedra that share corners with three equivalent CaO6 pentagonal pyramids, edges with six VO6 octahedra, and an edgeedge with one CaO6 pentagonal pyramid. There are a spread of V–O bond distances ranging from 2.02–2.12 Å. In the second V3+ site, V3+ is bonded to six O2- atoms to form VO6 octahedra that share edges with six VO6 octahedra and edges with two equivalent CaO6 pentagonal pyramids. There are four shorter (2.04 Å) and two longer (2.13 Å) V–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Ca2+ and three V3+ atoms. In the second O2- site, O2- is bonded to one Ca2+ and three V3+ atoms to form OCaV3 trigonal pyramids that share corners with four equivalent OCa2V3 trigonal bipyramids, corners with three equivalent OCaV3 trigonal pyramids, and edges with four equivalent OCa2V3 trigonal bipyramids. In the third O2- site, O2- is bonded to two Ca2+ and three V3+ atoms to form OCa2V3 trigonal bipyramids that share corners with five equivalent OCa2V3 trigonal bipyramids, corners with two equivalent OCaV3 trigonal pyramids, edges with four equivalent OCa2V3 trigonal bipyramids, and edges with two equivalent OCaV3 trigonal pyramids.