DOI: 10.17188/1300355
title: Materials Data on Nb2Ge2O7 by Materials Project

description: Nb2Ge2O7 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are four inequivalent Nb3+ sites. In the first Nb3+ site, Nb3+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 21–30°. There are a spread of Nb–O bond distances ranging from 1.88–2.21 Å. In the second Nb3+ site, Nb3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Nb–O bond distances ranging from 1.83–2.45 Å. In the third Nb3+ site, Nb3+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 21–31°. There are a spread of Nb–O bond distances ranging from 1.84–2.29 Å. In the fourth Nb3+ site, Nb3+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 5–31°. There are a spread of Nb–O bond distances ranging from 1.84–2.33 Å. There are four inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Ge–O bond distances ranging from 1.89–2.21 Å. In the second Ge4+ site, Ge4+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Ge–O bond distances ranging from 1.95–2.11 Å. In the third Ge4+ site, Ge4+ is bonded in a 3-coordinate geometry to three O2- atoms. There are one shorter (2.01 Å) and two longer (2.05 Å) Ge–O bond lengths. In the fourth Ge4+ site, Ge4+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Ge–O bond distances ranging from 2.01–2.21 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb3+ and one Ge4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Nb3+ and one Ge4+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Nb3+ atoms. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to two Nb3+ and one Ge4+ atom. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to one Nb3+ and one Ge4+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Nb3+ and one Ge4+ atom. In the seventh O2- site, O2- is bonded in a distorted linear geometry to two Nb3+ atoms. In the eighth O2- site, O2- is bonded in a trigonal planar geometry to one Nb3+ and two Ge4+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to two Nb3+ and one Ge4+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Nb3+ and one Ge4+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to two Nb3+ and one Ge4+ atom. In the twelfth O2- site, O2- is bonded in a trigonal planar geometry to one Nb3+ and two equivalent Ge4+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Nb3+ atoms. In the fourteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Nb3+ atoms.