DOI: 10.17188/1298322
title: Materials Data on Ho2Ge2O7 by Materials Project

description: Ho2Ge2O7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ho–O bond distances ranging from 2.24–2.41 Å. In the second Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.23–2.81 Å. In the third Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.31–2.62 Å. In the fourth Ho3+ site, Ho3+ is bonded to six O2- atoms to form distorted HoO6 octahedra that share corners with seven GeO4 tetrahedra. There are a spread of Ho–O bond distances ranging from 2.23–2.40 Å. There are four inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent HoO6 octahedra and a cornercorner with one GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–69°. There are a spread of Ge–O bond distances ranging from 1.75–1.80 Å. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share a cornercorner with one HoO6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Ge–O bond distances ranging from 1.74–1.81 Å. In the third Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with three equivalent HoO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 62–68°. There are a spread of Ge–O bond distances ranging from 1.74–1.80 Å. In the fourth Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share a cornercorner with one HoO6 octahedra and a cornercorner with one GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Ge–O bond distances ranging from 1.75–1.88 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded to three Ho3+ and one Ge4+ atom to form a mixture of distorted corner and edge-sharing OHo3Ge tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Ho3+ and one Ge4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ho3+ and one Ge4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Ge4+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ho3+ and one Ge4+ atom. In the seventh O2- site, O2- is bonded to three Ho3+ and one Ge4+ atom to form distorted corner-sharing OHo3Ge tetrahedra. In the eighth O2- site, O2- is bonded in a bent 120 degrees geometry to two Ge4+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Ge4+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ho3+ and one Ge4+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Ge4+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to two Ho3+ and one Ge4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ho3+ and one Ge4+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ho3+ and two Ge4+ atoms.