Materials Data on SrAl2(Si2O7)3 by Materials Project
SrAl2Si6O19O2 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional and consists of two hydrogen peroxide molecules and one SrAl2Si6O19 framework. In the SrAl2Si6O19 framework, Sr is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Sr–O bond distances ranging from 2.52–3.19 Å. 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 1.72–1.80 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 a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. 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 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 third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. There are twelve inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one Sr, one Al, and one Si atom. In the second O site, O is bonded in a single-bond geometry to one Sr atom. 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 two Si atoms. In the fifth O site, O is bonded in a linear geometry to two equivalent Si atoms. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Sr and two equivalent Si atoms. In the seventh O site, O is bonded in a 3-coordinate geometry to one Sr, one Al, and one Si atom. In the eighth O site, O is bonded in a single-bond geometry to one O atom. The O–O bond length is 1.23 Å. 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 one Sr and one O atom. In the eleventh O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the twelfth O site, O is bonded in a bent 150 degrees geometry to two Si atoms.