Materials Data on BaAl2Si3(W2O5)2 by Materials Project

Abstract

(W)2BaAl2Si3(WO5)2 crystallizes in the orthorhombic P2_12_12 space group. The structure is three-dimensional and consists of four wolfram molecules and one BaAl2Si3(WO5)2 framework. In the BaAl2Si3(WO5)2 framework, Ba2+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are four shorter (3.05 Å) and two longer (3.13 Å) Ba–O bond lengths. W2+ is bonded in a single-bond geometry to one O2- atom. The W–O bond length is 2.32 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.75–1.83 Å. There are two inequivalent Si+1.33+ sites. In the first Si+1.33+ site, Si+1.33+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three equivalent AlO4 tetrahedra. There is three shorter (1.64 Å) and one longer (1.66 Å) Si–O bond length. In the second Si+1.33+ site, Si+1.33+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.64 Å) and two longer (1.65 Å) Si–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two Si+1.33+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Al3+, and one Si+1.33+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one W2+, one Al3+, and one Si+1.33+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ba2+, one Al3+, and one Si+1.33+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ba2+, one Al3+, and one Si+1.33+ atom.