Materials Data on BaCu2Si2O7 by Materials Project
BaCu2Si2O7 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ba2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.75–2.96 Å. Cu2+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.93–1.99 Å. Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.63–1.68 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Cu2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and two equivalent Si4+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cu2+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, one Cu2+, and one Si4+ atom.