Materials Data on CaAl2Si2(ClO4)2 by Materials Project
CaAl2Si2(O4Cl)2 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are three inequivalent Ca sites. In the first Ca site, Ca is bonded in a 6-coordinate geometry to three equivalent O and three equivalent Cl atoms. All Ca–O bond lengths are 2.32 Å. All Ca–Cl bond lengths are 2.85 Å. In the second Ca site, Ca is bonded in a 6-coordinate geometry to three equivalent O and three equivalent Cl atoms. All Ca–O bond lengths are 2.39 Å. All Ca–Cl bond lengths are 2.81 Å. In the third Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are three shorter (2.46 Å) and three longer (2.85 Å) Ca–O bond lengths. Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.73–1.82 Å. 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 are a spread of Si–O bond distances ranging from 1.59–1.72 Å. There are six inequivalent O sites. In the first O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent Si atoms. In the second O site, O is bonded to two Ca and two equivalent Al atoms to form distorted edge-sharing OCa2Al2 tetrahedra. In the third O site, O is bonded in a 4-coordinate geometry to two Ca and two equivalent Si atoms. In the fourth O site, O is bonded in a linear geometry to 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 120 degrees geometry to two equivalent Al atoms. There are two inequivalent Cl sites. In the first Cl site, Cl is bonded in a single-bond geometry to one Ca atom. In the second Cl site, Cl is bonded in a single-bond geometry to one Ca atom.