Materials Data on CaNb2O4 by Materials Project

CaNb2O4 crystallizes in the orthorhombic Pbcm space group. The structure is three-dimensional. Ca2+ is bonded to six O2- atoms to form distorted CaO6 pentagonal pyramids that share corners with nine NbO6 pentagonal pyramids, edges with two equivalent CaO6 pentagonal pyramids, edges with three NbO6 pentagonal pyramids, and a faceface with one NbO6 pentagonal pyramid. There are a spread of Ca–O bond distances ranging from 2.29–2.46 Å. There are two inequivalent Nb3+ sites. In the first Nb3+ site, Nb3+ is bonded to six O2- atoms to form distorted NbO6 pentagonal pyramids that share corners with four equivalent CaO6 pentagonal pyramids, edges with two equivalent CaO6 pentagonal pyramids, and edges with six NbO6 pentagonal pyramids. There are a spread of Nb–O bond distances ranging from 2.14–2.19 Å. In the second Nb3+ site, Nb3+ is bonded to six O2- atoms to form distorted NbO6 pentagonal pyramids that share corners with five equivalent CaO6 pentagonal pyramids, an edgeedge with one CaO6 pentagonal pyramid, edges with six NbO6 pentagonal pyramids, and a faceface with one CaO6 pentagonal pyramid. There are a spread of Nb–O bond distances ranging from 2.13–2.19 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Nb3+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Nb3+ atoms. In the third O2- site, O2- is bonded to two equivalent Ca2+ and three Nb3+ atoms to form a mixture of edge, face, and corner-sharing OCa2Nb3 trigonal bipyramids.