Materials Data on Sr2ZnGe2O7 by Materials Project

Abstract

Sr2ZnGe2O7 crystallizes in the tetragonal P-42_1m space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.59–2.91 Å. Zn2+ is bonded to four equivalent O2- atoms to form ZnO4 tetrahedra that share corners with four equivalent GeO4 tetrahedra. All Zn–O bond lengths are 1.98 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share a cornercorner with one GeO4 tetrahedra and corners with two equivalent ZnO4 tetrahedra. There are a spread of Ge–O bond distances ranging from 1.74–1.82 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Sr2+, one Zn2+, and one Ge4+ atom. In the second O2- site, O2- is bonded to three equivalent Sr2+ and one Ge4+ atom to form a mixture of distorted edge and corner-sharing OSr3Ge tetrahedra. In the third O2- site, O2- is bonded to two equivalent Sr2+ and two equivalent Ge4+ atoms to form a mixture of distorted edge and corner-sharing OSr2Ge2 tetrahedra.