Materials Data on Ca2NbO6F by Materials Project

Abstract

Ca2NbO6F crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a body-centered cubic geometry to six O and two equivalent F atoms. There are four shorter (2.40 Å) and two longer (2.54 Å) Ca–O bond lengths. Both Ca–F bond lengths are 2.30 Å. In the second Ca site, Ca is bonded in a distorted body-centered cubic geometry to six O and two equivalent F atoms. There are four shorter (2.54 Å) and two longer (2.57 Å) Ca–O bond lengths. Both Ca–F bond lengths are 2.23 Å. Nb is bonded to six O atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 42°. There are four shorter (2.00 Å) and two longer (2.05 Å) Nb–O bond lengths. There are three inequivalent O sites. In the first O site, O is bonded in a trigonal non-coplanar geometry to two Ca and one Nb atom. In the second O site, O is bonded in a water-like geometry to two equivalent Ca atoms. In the third O site, O is bonded to two equivalent Ca and two equivalent Nb atoms to form distorted OCa2Nb2 trigonal pyramids that share corners with two equivalent FCa4 tetrahedra, corners with four equivalent OCa2Nb2 trigonal pyramids, and an edgeedge with one FCa4 tetrahedra. F is bonded to four Ca atoms to form FCa4 tetrahedra that share corners with four equivalent FCa4 tetrahedra, corners with two equivalent OCa2Nb2 trigonal pyramids, and an edgeedge with one OCa2Nb2 trigonal pyramid.