Materials Data on NaAlGeO4 by Materials Project

Abstract

NaAlGeO4 crystallizes in the orthorhombic Pmc2_1 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.36–2.56 Å. In the second Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–2.52 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with four equivalent GeO6 octahedra, edges with two equivalent AlO6 octahedra, and edges with two equivalent GeO6 octahedra. The corner-sharing octahedra tilt angles range from 48–56°. There are a spread of Al–O bond distances ranging from 1.93–2.00 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with four equivalent GeO6 octahedra, edges with two equivalent AlO6 octahedra, and edges with two equivalent GeO6 octahedra. The corner-sharing octahedra tilt angles range from 48–53°. There are a spread of Al–O bond distances ranging from 1.91–2.03 Å. There are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with four equivalent AlO6 octahedra, edges with two equivalent AlO6 octahedra, and edges with two equivalent GeO6 octahedra. The corner-sharing octahedra tilt angles range from 48–53°. There are a spread of Ge–O bond distances ranging from 1.93–1.97 Å. In the second Ge4+ site, Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with four equivalent AlO6 octahedra, edges with two equivalent AlO6 octahedra, and edges with two equivalent GeO6 octahedra. The corner-sharing octahedra tilt angles range from 48–56°. There are a spread of Ge–O bond distances ranging from 1.93–1.96 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Na1+, one Al3+, and two equivalent Ge4+ atoms to form a mixture of distorted edge and corner-sharing ONa2AlGe2 square pyramids. In the second O2- site, O2- is bonded to two equivalent Na1+, two equivalent Al3+, and one Ge4+ atom to form a mixture of distorted edge and corner-sharing ONa2Al2Ge square pyramids. In the third O2- site, O2- is bonded to two equivalent Na1+, one Al3+, and two equivalent Ge4+ atoms to form a mixture of distorted edge and corner-sharing ONa2AlGe2 trigonal bipyramids. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two equivalent Al3+, and one Ge4+ atom. In the fifth O2- site, O2- is bonded to two equivalent Na1+, one Al3+, and two equivalent Ge4+ atoms to form a mixture of distorted edge and corner-sharing ONa2AlGe2 trigonal bipyramids. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two equivalent Al3+, and one Ge4+ atom. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, one Al3+, and two equivalent Ge4+ atoms. In the eighth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two equivalent Al3+, and one Ge4+ atom.