Materials Data on Ca2AgSbO6 by Materials Project

Abstract

Ca2AgSbO6 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.42–2.63 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 pentagonal pyramids that share corners with two equivalent SbO6 octahedra, edges with two equivalent SbO6 octahedra, and edges with two equivalent CaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 56°. There are a spread of Ca–O bond distances ranging from 2.31–2.62 Å. Ag3+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are two shorter (2.04 Å) and two longer (2.07 Å) Ag–O bond lengths. Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with two equivalent SbO6 octahedra, corners with two equivalent CaO6 pentagonal pyramids, and edges with two equivalent CaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 41°. There are a spread of Sb–O bond distances ranging from 1.98–2.06 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ca2+, one Ag3+, and one Sb5+ atom to form distorted OCa2AgSb trigonal pyramids that share corners with two equivalent OCa2Sb2 tetrahedra, corners with eight OCa2AgSb trigonal pyramids, an edgeedge with one OCa2Sb2 tetrahedra, and edges with two OCa2Ag2 trigonal pyramids. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three Ca2+ and one Sb5+ atom. In the third O2- site, O2- is bonded to two Ca2+ and two equivalent Sb5+ atoms to form OCa2Sb2 tetrahedra that share corners with two equivalent OCa2Sb2 tetrahedra, corners with six OCa2AgSb trigonal pyramids, and edges with two equivalent OCa2AgSb trigonal pyramids. In the fourth O2- site, O2- is bonded to two Ca2+ and two equivalent Ag3+ atoms to form distorted OCa2Ag2 trigonal pyramids that share corners with two equivalent OCa2Sb2 tetrahedra, corners with six OCa2Ag2 trigonal pyramids, and edges with two equivalent OCa2AgSb trigonal pyramids.