Materials Data on Ca2Al3Si3O13 by Materials Project

Abstract

Ca2Al3Si3O13 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.67 Å. In the second Ca site, Ca is bonded in a 1-coordinate geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.23–2.75 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded to six O atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with four SiO4 tetrahedra, and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.86–2.05 Å. In the second Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with two equivalent AlO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Al–O bond distances ranging from 1.75–1.83 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent AlO6 octahedra, a cornercorner with one AlO4 tetrahedra, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Si–O bond distances ranging from 1.61–1.65 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of Si–O bond distances ranging from 1.60–1.65 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four equivalent AlO6 octahedra and corners with two equivalent AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–48°. There is one shorter (1.65 Å) and three longer (1.66 Å) Si–O bond length. There are ten inequivalent O sites. In the first O site, O is bonded in a distorted trigonal planar geometry to one Ca, one Al, and one Si atom. In the second O site, O is bonded in a 4-coordinate geometry to one Ca, two equivalent Al, and one Si atom. In the third O site, O is bonded in a 3-coordinate geometry to two Ca and one Si atom. In the fourth O site, O is bonded in a 2-coordinate geometry to two equivalent Ca, one Al, and one Si atom. In the fifth O site, O is bonded in a linear geometry to one Al and one Si atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the seventh O site, O is bonded in a 4-coordinate geometry to one Ca, two equivalent Al, and one Si atom. In the eighth O site, O is bonded in a 4-coordinate geometry to two Ca, one Al, and one Si atom. In the ninth O site, O is bonded in a distorted water-like geometry to one Ca and two equivalent Al atoms. In the tenth O site, O is bonded in a trigonal planar geometry to three Al atoms.