Materials Data on Ba2CdSe3 by Materials Project
Ba2CdSe3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to seven Se2- atoms to form distorted BaSe7 pentagonal bipyramids that share corners with three equivalent BaSe7 pentagonal bipyramids, corners with four equivalent CdSe4 tetrahedra, edges with eleven BaSe7 pentagonal bipyramids, and edges with three equivalent CdSe4 tetrahedra. There are a spread of Ba–Se bond distances ranging from 3.26–3.58 Å. In the second Ba2+ site, Ba2+ is bonded to seven Se2- atoms to form distorted BaSe7 pentagonal bipyramids that share corners with seven BaSe7 pentagonal bipyramids, edges with seven BaSe7 pentagonal bipyramids, edges with four equivalent CdSe4 tetrahedra, and faces with two equivalent BaSe7 pentagonal bipyramids. There are a spread of Ba–Se bond distances ranging from 3.37–3.49 Å. Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with four equivalent BaSe7 pentagonal bipyramids, corners with two equivalent CdSe4 tetrahedra, and edges with seven BaSe7 pentagonal bipyramids. There are a spread of Cd–Se bond distances ranging from 2.67–2.72 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to four Ba2+ and two equivalent Cd2+ atoms. In the second Se2- site, Se2- is bonded to five Ba2+ and one Cd2+ atom to form a mixture of distorted edge, face, and corner-sharing SeBa5Cd octahedra. The corner-sharing octahedra tilt angles range from 52–57°. In the third Se2- site, Se2- is bonded to five Ba2+ and one Cd2+ atom to form a mixture of distorted edge, face, and corner-sharing SeBa5Cd octahedra. The corner-sharing octahedra tilt angles range from 22–57°.