DOI: 10.17188/1685765
title: Materials Data on CaAl2Si4O15 by Materials Project

description: CaAl2Si4O15 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.86 Å. There are two 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 is two shorter (1.73 Å) and two longer (1.80 Å) Al–O bond length. In the second Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There is two shorter (1.73 Å) and two longer (1.80 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 two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.65 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.65 Å. There are fifteen inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the second O site, O is bonded in a bent 150 degrees geometry to two Si 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 bent 150 degrees geometry to one Al and one Si atom. In the fifth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the sixth O site, O is bonded in a distorted trigonal planar geometry to one Ca, one Al, and one Si atom. In the seventh O site, O is bonded in a distorted trigonal planar 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 bent 150 degrees geometry to one Al and one Si atom. In the tenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eleventh O site, O is bonded in a distorted trigonal planar geometry to one Ca, one Al, and one Si atom. In the twelfth O site, O is bonded in a distorted trigonal planar geometry to one Ca, one Al, and one Si atom. In the thirteenth O site, O is bonded in a bent 120 degrees geometry to two O atoms. There is one shorter (1.29 Å) and one longer (1.31 Å) O–O bond length. In the fourteenth O site, O is bonded in a water-like geometry to one Ca and one O atom. In the fifteenth O site, O is bonded in an L-shaped geometry to one Ca and one O atom.