Materials Data on Cs3TaO8 by Materials Project

Abstract

Cs3TaO8 crystallizes in the tetragonal I-42m space group. The structure is three-dimensional. there are two inequivalent Cs sites. In the first Cs site, Cs is bonded to eight O atoms to form CsO8 hexagonal bipyramids that share corners with four equivalent TaO8 hexagonal bipyramids, corners with four equivalent OCs3TaO trigonal bipyramids, and edges with two equivalent TaO8 hexagonal bipyramids. There are four shorter (3.07 Å) and four longer (3.26 Å) Cs–O bond lengths. In the second Cs site, Cs is bonded in a 4-coordinate geometry to twelve O atoms. There are a spread of Cs–O bond distances ranging from 3.03–3.56 Å. Ta is bonded to eight O atoms to form distorted TaO8 hexagonal bipyramids that share corners with four equivalent CsO8 hexagonal bipyramids, corners with four equivalent OCs3TaO trigonal bipyramids, and edges with two equivalent CsO8 hexagonal bipyramids. There are four shorter (2.03 Å) and four longer (2.08 Å) Ta–O bond lengths. There are two inequivalent O sites. In the first O site, O is bonded to three Cs, one Ta, and one O atom to form distorted OCs3TaO trigonal bipyramids that share a cornercorner with one CsO8 hexagonal bipyramid, a cornercorner with one TaO8 hexagonal bipyramid, corners with ten equivalent OCs3TaO trigonal bipyramids, and an edgeedge with one OCs3TaO trigonal bipyramid. The O–O bond length is 1.51 Å. In the second O site, O is bonded in a 1-coordinate geometry to five Cs, one Ta, and one O atom.