Materials Data on Ca4Be2Al2Si9O28 by Materials Project

Ca4Be2Al2Si9O28 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.71 Å. Be is bonded to four O atoms to form BeO4 tetrahedra that share corners with three SiO4 tetrahedra. There are a spread of Be–O bond distances ranging from 1.62–1.72 Å. Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There is two shorter (1.75 Å) and two 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 two equivalent BeO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.64 Å) and two longer (1.67 Å) Si–O bond length. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one BeO4 tetrahedra and corners with three SiO4 tetrahedra. There is one shorter (1.62 Å) and three longer (1.64 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 two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.63 Å) and two longer (1.65 Å) Si–O bond length. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with two equivalent AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.71 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent Ca and two Si atoms. 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 two equivalent Ca and one Be atom. In the fourth O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent Ca, one Be, and one Si atom. In the fifth O site, O is bonded in a bent 150 degrees geometry to two equivalent Si atoms. 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 2-coordinate geometry to one Ca, one Al, and one Si atom. In the eighth O site, O is bonded in a trigonal planar geometry to two equivalent Ca and one Si atom. In the ninth O site, O is bonded in a 3-coordinate geometry to one Ca, one Be, and one Si atom.