Materials Data on Cs2Th(AsO4)2 by Materials Project
Cs2Th(AsO4)2 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. Cs1+ is bonded to four equivalent O2- atoms to form distorted CsO4 hexagonal bipyramids that share corners with four equivalent ThO8 hexagonal bipyramids, corners with four equivalent AsO4 tetrahedra, and edges with two equivalent CsO4 hexagonal bipyramids. All Cs–O bond lengths are 3.03 Å. Th4+ is bonded to eight O2- atoms to form distorted ThO8 hexagonal bipyramids that share corners with eight equivalent CsO4 hexagonal bipyramids, corners with four equivalent AsO4 tetrahedra, and edges with two equivalent AsO4 tetrahedra. There are four shorter (2.37 Å) and four longer (2.55 Å) Th–O bond lengths. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent ThO8 hexagonal bipyramids, corners with four equivalent CsO4 hexagonal bipyramids, and an edgeedge with one ThO8 hexagonal bipyramid. All As–O bond lengths are 1.72 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Th4+ and one As5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Cs1+, one Th4+, and one As5+ atom.