Materials Data on CaGe2O5 by Materials Project

Abstract

CaGe2O5 is Esseneite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.90 Å. In the second Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.93 Å. There are four inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four O2- atoms to form corner-sharing GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 43–57°. There is two shorter (1.77 Å) and two longer (1.78 Å) Ge–O bond length. In the second Ge4+ site, Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with two equivalent GeO6 octahedra and corners with four GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. There are a spread of Ge–O bond distances ranging from 1.85–2.00 Å. In the third Ge4+ site, Ge4+ is bonded to four O2- atoms to form corner-sharing GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 43–57°. There is two shorter (1.77 Å) and two longer (1.78 Å) Ge–O bond length. In the fourth Ge4+ site, Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with two equivalent GeO6 octahedra and corners with four GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. There are a spread of Ge–O bond distances ranging from 1.86–1.98 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Ge4+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Ge4+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Ge4+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Ge4+ atoms. In the fifth O2- site, O2- is bonded to two Ca2+ and two Ge4+ atoms to form a mixture of distorted corner and edge-sharing OCa2Ge2 tetrahedra. In the sixth O2- site, O2- is bonded to two Ca2+ and two Ge4+ atoms to form a mixture of distorted corner and edge-sharing OCa2Ge2 tetrahedra. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Ge4+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Ge4+ atoms. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Ge4+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Ge4+ atoms.