Materials Data on Ba2Ge2Se5 by Materials Project

Ba2Ge2Se5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.40–3.61 Å. There are two inequivalent Ge3+ sites. In the first Ge3+ site, Ge3+ is bonded in a 5-coordinate geometry to five Se2- atoms. There are a spread of Ge–Se bond distances ranging from 2.48–3.27 Å. In the second Ge3+ site, Ge3+ is bonded in a tetrahedral geometry to four Se2- atoms. There are a spread of Ge–Se bond distances ranging from 2.36–2.40 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four equivalent Ba2+ and one Ge3+ atom to form a mixture of distorted edge and corner-sharing SeBa4Ge square pyramids. In the second Se2- site, Se2- is bonded to four equivalent Ba2+ and one Ge3+ atom to form a mixture of distorted face, edge, and corner-sharing SeBa4Ge square pyramids. In the third Se2- site, Se2- is bonded to four equivalent Ba2+ and one Ge3+ atom to form a mixture of distorted face, edge, and corner-sharing SeBa4Ge square pyramids. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Ba2+ and three Ge3+ atoms.