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.

CaNb2O4结晶于正交晶系Pbcm空间群。该结构为三维骨架结构。Ca²+与6个O²-配位，形成畸变CaO6五方锥；该五方锥分别与9个NbO6五方锥共享顶点、与2个等价CaO6五方锥共享棱、与3个NbO6五方锥共享棱，并与1个NbO6五方锥共面。Ca-O键的键长分布范围为2.29~2.46 Å。
存在两个不等价的Nb³+配位位点。在第一个Nb³+位点中，Nb³+与6个O²-配位，形成畸变NbO6五方锥；该五方锥分别与4个等价CaO6五方锥共享顶点、与2个等价CaO6五方锥共享棱，并与6个NbO6五方锥共享棱。Nb-O键的键长分布范围为2.14~2.19 Å。
在第二个Nb³+位点中，Nb³+与6个O²-配位，形成畸变NbO6五方锥；该五方锥分别与5个等价CaO6五方锥共享顶点、与1个CaO6五方锥共享棱、与6个NbO6五方锥共享棱，并与1个CaO6五方锥共面。Nb-O键的键长分布范围为2.13~2.19 Å。
存在三个不等价的O²-配位位点。在第一个O²-位点中，O²-以矩形跷跷板状几何构型与1个Ca²+和3个Nb³+配位。在第二个O²-位点中，O²-以矩形跷跷板状几何构型与1个Ca²+和3个Nb³+配位。在第三个O²-位点中，O²-与2个等价Ca²+和3个Nb³+配位，形成兼具边共享、面共享和顶点共享的OCa2Nb3三角双锥结构。