DOI: 10.17188/1725590
title: Materials Data on CaAl2(SiO5)2 by Materials Project

description: CaAl2(SiO5)2 crystallizes in the orthorhombic P2_12_12_1 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 2.29–2.82 Å. In the second 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 2.35–2.72 Å. There are four inequivalent Al sites. In the first Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.72–1.79 Å. In the second Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.74–1.79 Å. In the third Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.72–1.82 Å. In the fourth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There is three shorter (1.75 Å) and one longer (1.76 Å) Al–O bond length. There are four inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO4 tetrahedra. There is one shorter (1.61 Å) and three longer (1.66 Å) Si–O bond length. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.68 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. There are twenty inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to one Ca, one Al, and one Si atom. In the second O site, O is bonded in a 3-coordinate geometry to one Ca, one Al, and one Si atom. In the third O site, O is bonded in a distorted trigonal planar geometry to one Ca, one Al, and one Si atom. In the fourth O site, O is bonded in a 3-coordinate geometry to one Ca, one Al, and one Si atom. In the fifth O site, O is bonded in a 3-coordinate geometry to one Ca, one Al, and one Si atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the seventh O site, O is bonded in a 3-coordinate geometry to one Ca, one Al, and one Si atom. 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 3-coordinate geometry to one Ca, one Al, and one Si atom. In the tenth O site, O is bonded in a bent 120 degrees geometry to one Al and one Si atom. In the eleventh O site, O is bonded in a bent 120 degrees geometry to one Al and one Si atom. In the twelfth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the thirteenth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the fourteenth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the fifteenth O site, O is bonded in a 3-coordinate geometry to one Ca, one Al, and one Si atom. In the sixteenth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the seventeenth O site, O is bonded in a distorted trigonal non-coplanar geometry to two Ca and one O atom. The O–O bond length is 1.24 Å. In the eighteenth O site, O is bonded in a single-bond geometry to one O atom. In the nineteenth O site, O is bonded in a distorted trigonal planar geometry to two Ca and one O atom. The O–O bond length is 1.24 Å. In the twentieth O site, O is bonded in a 2-coordinate geometry to one Ca and one O atom.