Materials Data on Er2Be2GeO7 by Materials Project
Be2Er2GeO7 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 are a spread of Be–O bond distances ranging from 1.57–1.70 Å. Er3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Er–O bond distances ranging from 2.24–2.58 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 1.76 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 Er3+, and one Ge4+ atom. In the second O2- site, O2- is bonded in a distorted tetrahedral geometry to two equivalent Be2+ and two equivalent Er3+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Be2+ and three equivalent Er3+ atoms.