Materials Data on BaCu(SiO3)2 by Materials Project

Abstract

BaCuSi2O6 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba2+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are eight shorter (2.97 Å) and four longer (3.29 Å) Ba–O bond lengths. Cu2+ is bonded in a rectangular see-saw-like geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.96 Å. Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is two shorter (1.63 Å) and two longer (1.65 Å) Si–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+, one Cu2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ba2+ and two equivalent Si4+ atoms.