Materials Data on La2Be2GeO7 by Materials Project

Abstract

Be2La2GeO7 crystallizes in the tetragonal P-42_1m space group. The structure is three-dimensional. Be2+ is bonded to four O2- atoms to form BeO4 tetrahedra that share a cornercorner with one BeO4 tetrahedra and corners with two equivalent GeO4 tetrahedra. There is two shorter (1.59 Å) and two longer (1.75 Å) Be–O bond length. La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.41–2.71 Å. Ge4+ is bonded to four equivalent O2- atoms to form GeO4 tetrahedra that share corners with four equivalent BeO4 tetrahedra. All Ge–O bond lengths are 1.78 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Be2+, two equivalent La3+, and one Ge4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Be2+ and two equivalent La3+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Be2+ and three equivalent La3+ atoms.