Materials Data on Ta2Ge2O7 by Materials Project
Ta2Ge2O7 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent Ta3+ sites. In the first Ta3+ site, Ta3+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 13–25°. There are a spread of Ta–O bond distances ranging from 1.92–2.13 Å. In the second Ta3+ site, Ta3+ is bonded to six O2- atoms to form distorted corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 2–29°. There are a spread of Ta–O bond distances ranging from 1.86–2.23 Å. There are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ge–O bond distances ranging from 2.01–2.47 Å. In the second Ge4+ site, Ge4+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ge–O bond distances ranging from 2.06–2.20 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted see-saw-like geometry to two Ta3+ and two equivalent Ge4+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent Ta3+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Ta3+ and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a linear geometry to two Ta3+ atoms. In the fifth O2- site, O2- is bonded to one Ta3+ and three equivalent Ge4+ atoms to form distorted corner-sharing OTaGe3 tetrahedra. In the sixth O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ta3+ and one Ge4+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ta3+ and one Ge4+ atom.