Materials Data on CdSe2O9 by Materials Project
(Cd(SeO4)2)2O2 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four water molecules and two Cd(SeO4)2 sheets oriented in the (0, 0, 1) direction. In each Cd(SeO4)2 sheet, Cd is bonded to six O atoms to form CdO6 octahedra that share corners with six SeO4 tetrahedra. There are a spread of Cd–O bond distances ranging from 2.28–2.35 Å. There are two inequivalent Se sites. In the first Se site, Se is bonded to four O atoms to form SeO4 tetrahedra that share corners with three equivalent CdO6 octahedra. The corner-sharing octahedra tilt angles range from 49–56°. There are a spread of Se–O bond distances ranging from 1.67–1.72 Å. In the second Se site, Se is bonded to four O atoms to form SeO4 tetrahedra that share corners with three equivalent CdO6 octahedra. The corner-sharing octahedra tilt angles range from 47–56°. There are a spread of Se–O bond distances ranging from 1.67–1.71 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to one Cd and one Se atom. In the second O site, O is bonded in a distorted bent 120 degrees geometry to one Cd and one Se atom. In the third O site, O is bonded in a single-bond geometry to one Se atom. In the fourth O site, O is bonded in a bent 120 degrees geometry to one Cd and one Se atom. In the fifth O site, O is bonded in a bent 120 degrees geometry to one Cd and one Se atom. In the sixth O site, O is bonded in a bent 120 degrees geometry to one Cd and one Se atom. In the seventh O site, O is bonded in a single-bond geometry to one Se atom. In the eighth O site, O is bonded in a bent 120 degrees geometry to one Cd and one Se atom.