Materials Data on Eu2Ge2O7 by Materials Project
Eu2Ge2O7 crystallizes in the tetragonal P4_12_12 space group. The structure is three-dimensional. Eu3+ is bonded to seven O2- atoms to form distorted EuO7 pentagonal bipyramids that share corners with five equivalent GeO4 tetrahedra, edges with five equivalent EuO7 pentagonal bipyramids, and an edgeedge with one GeO4 tetrahedra. There are a spread of Eu–O bond distances ranging from 2.31–2.68 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with five equivalent EuO7 pentagonal bipyramids, a cornercorner with one GeO4 tetrahedra, and an edgeedge with one EuO7 pentagonal bipyramid. There is two shorter (1.76 Å) and two longer (1.80 Å) Ge–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ge4+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Eu3+ and one Ge4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Eu3+ and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Eu3+ and one Ge4+ atom.