DOI: 10.17188/1679646
title: Materials Data on Ca2Al3Si3O13 by Materials Project

description: Ca2Al3Si3O13 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.52 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 2.28–2.74 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with four AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.85–1.98 Å. In the second Al site, Al is bonded to six O atoms to form distorted AlO6 octahedra that share corners with five SiO4 tetrahedra and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.81–2.29 Å. In the third Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.85–1.97 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 three AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 29–52°. There are a spread of Si–O bond distances ranging from 1.60–1.65 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with six AlO6 octahedra. The corner-sharing octahedra tilt angles range from 46–53°. There is three shorter (1.65 Å) and one longer (1.67 Å) Si–O bond length. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–56°. There is one shorter (1.59 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 2-coordinate geometry to two equivalent Ca, one Al, and one Si atom. In the second O site, O is bonded in a trigonal non-coplanar geometry to one Ca and two equivalent Al atoms. In the third O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fourth O site, O is bonded in a 3-coordinate geometry to two equivalent Al and one Si atom. In the fifth O site, O is bonded in a trigonal non-coplanar geometry to three Al atoms. In the sixth O site, O is bonded in a distorted trigonal planar geometry to two Ca and one Si atom. In the seventh O site, O is bonded to one Ca, two Al, and one Si atom to form a mixture of distorted corner and edge-sharing OCaAl2Si tetrahedra. In the eighth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the ninth O site, O is bonded in a 4-coordinate geometry to one Ca, two equivalent Al, and one Si atom. In the tenth O site, O is bonded in a 2-coordinate geometry to two Ca, one Al, and one Si atom.