Materials Data on CuGeO3 by Materials Project

CuGeO3 crystallizes in the orthorhombic Pbam space group. The structure is two-dimensional and consists of two CuGeO3 sheets oriented in the (0, 1, 0) direction. there are six inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.96 Å. In the second Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to four O2- atoms. All Cu–O bond lengths are 1.95 Å. In the third Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.95 Å. In the fourth Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.95 Å. In the fifth Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to four O2- atoms. All Cu–O bond lengths are 1.94 Å. In the sixth Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.95 Å. There are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four O2- atoms to form corner-sharing GeO4 tetrahedra. There is two shorter (1.77 Å) and two longer (1.80 Å) Ge–O bond length. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form corner-sharing GeO4 tetrahedra. There are a spread of Ge–O bond distances ranging from 1.77–1.80 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Ge4+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cu2+ and one Ge4+ atom. In the third O2- site, O2- is bonded in a water-like geometry to two Ge4+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cu2+ and one Ge4+ atom. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Ge4+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cu2+ and one Ge4+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cu2+ and one Ge4+ atom.