Materials Data on CdSe2O9 by Materials Project
(Cd(SeO3)2)2(O2)3 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four trioxidane molecules and two Cd(SeO3)2 sheets oriented in the (0, 0, 1) direction. In each Cd(SeO3)2 sheet, Cd is bonded in a distorted octahedral geometry to six O atoms. There are a spread of Cd–O bond distances ranging from 2.25–2.66 Å. There are two inequivalent Se sites. In the first Se site, Se is bonded in a distorted trigonal non-coplanar geometry to three O atoms. There are a spread of Se–O bond distances ranging from 1.64–2.12 Å. In the second Se site, Se is bonded in a trigonal non-coplanar geometry to three O atoms. There are a spread of Se–O bond distances ranging from 1.66–2.07 Å. There are six inequivalent O sites. In the first O site, O is bonded in a trigonal planar geometry to one Cd and two Se atoms. In the second O site, O is bonded in a bent 150 degrees geometry to one Cd and one Se atom. In the third O site, O is bonded in a bent 120 degrees geometry to one Cd and one O atom. The O–O bond length is 1.34 Å. 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 trigonal non-coplanar geometry to one Cd, one Se, and one O atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Cd and one Se atom.