Materials Data on K2ErSbO7 by Materials Project

Abstract

K2ErSbO7 crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to eight O atoms to form KO8 hexagonal bipyramids that share corners with two equivalent KO8 hexagonal bipyramids, corners with two equivalent SbO6 octahedra, edges with four equivalent KO8 hexagonal bipyramids, edges with two equivalent SbO6 octahedra, and edges with four equivalent ErO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of K–O bond distances ranging from 2.65–3.10 Å. In the second K site, K is bonded to eight O atoms to form distorted KO8 hexagonal bipyramids that share edges with six KO8 hexagonal bipyramids, edges with two equivalent ErO6 octahedra, and edges with four equivalent SbO6 octahedra. There are four shorter (2.77 Å) and four longer (3.16 Å) K–O bond lengths. Er is bonded to six O atoms to form ErO6 octahedra that share corners with two equivalent ErO6 octahedra, corners with four equivalent SbO6 octahedra, and edges with six KO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 34–50°. There are two shorter (2.21 Å) and four longer (2.25 Å) Er–O bond lengths. Sb is bonded to six O atoms to form SbO6 octahedra that share corners with two equivalent KO8 hexagonal bipyramids, corners with four equivalent ErO6 octahedra, and edges with six KO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 34–35°. There are a spread of Sb–O bond distances ranging from 1.97–2.00 Å. There are six inequivalent O sites. In the first O site, O is bonded in a distorted rectangular see-saw-like geometry to three K and one Sb atom. In the second O site, O is bonded in a 2-coordinate geometry to two K, one Er, and one Sb atom. In the third O site, O is bonded in a 2-coordinate geometry to two K, one Er, and one Sb atom. In the fourth O site, O is bonded in a 2-coordinate geometry to two equivalent K and two equivalent Er atoms. In the fifth O site, O is bonded in a distorted rectangular see-saw-like geometry to three K and one Sb atom. In the sixth O site, O is bonded in a 2-coordinate geometry to two equivalent K and two equivalent Er atoms.