Materials Data on Ba(AlSe2)2 by Materials Project

Abstract

BaAl2Se4 crystallizes in the orthorhombic Pnnn space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are four shorter (3.43 Å) and four longer (3.45 Å) Ba–Se bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are four shorter (3.43 Å) and four longer (3.45 Å) Ba–Se bond lengths. Al3+ is bonded to four Se2- atoms to form edge-sharing AlSe4 tetrahedra. There are a spread of Al–Se bond distances ranging from 2.40–2.44 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to two Ba2+ and two equivalent Al3+ atoms. In the second Se2- site, Se2- is bonded to two Ba2+ and two equivalent Al3+ atoms to form a mixture of distorted edge and corner-sharing SeBa2Al2 trigonal pyramids.