Materials Data on CdBiSe2I by Materials Project
CdBiSe2I crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to six Se2- atoms to form CdSe6 octahedra that share corners with two equivalent CdSe2I4 octahedra, corners with four equivalent BiSe5 square pyramids, edges with two equivalent CdSe6 octahedra, and edges with six equivalent BiSe5 square pyramids. The corner-sharing octahedral tilt angles are 47°. There are two shorter (2.76 Å) and four longer (2.96 Å) Cd–Se bond lengths. In the second Cd2+ site, Cd2+ is bonded to two equivalent Se2- and four equivalent I1- atoms to form CdSe2I4 octahedra that share corners with two equivalent CdSe6 octahedra, corners with four equivalent BiSe5 square pyramids, and edges with two equivalent CdSe2I4 octahedra. The corner-sharing octahedral tilt angles are 47°. Both Cd–Se bond lengths are 2.89 Å. All Cd–I bond lengths are 2.99 Å. Bi3+ is bonded to five Se2- atoms to form distorted BiSe5 square pyramids that share corners with four CdSe6 octahedra, edges with three equivalent CdSe6 octahedra, and edges with four equivalent BiSe5 square pyramids. The corner-sharing octahedra tilt angles range from 13–65°. There are a spread of Bi–Se bond distances ranging from 2.74–3.16 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Cd2+ and three equivalent Bi3+ atoms to form a mixture of distorted edge and corner-sharing SeCd2Bi3 square pyramids. In the second Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to two Cd2+ and two equivalent Bi3+ atoms. I1- is bonded in an L-shaped geometry to two equivalent Cd2+ atoms.