DOE OSTI2020
BaAl2Si2O8O2 crystallizes in the monoclinic Pm space group. The structure is two-dimensional and consists of eight hydrogen peroxide molecules and one BaAl2Si2O8 sheet oriented in the (0, 0, 1) direction. In the BaAl2Si2O8 sheet, there are five inequivalent Ba sites. In the first Ba site, Ba is bonded in a 3-coordinate geometry to three O atoms. There are one shorter (2.61 Å) and two longer (2.62 Å) Ba–O bond lengths. In the second Ba site, Ba is bonded in a 3-coordinate geometry to three O atoms. There are two shorter (2.62 Å) and one longer (2.63 Å) Ba–O bond lengths. In the third Ba site, Ba is bonded in a 3-coordinate geometry to three O atoms. All Ba–O bond lengths are 2.63 Å. In the fourth Ba site, Ba is bonded in a 3-coordinate geometry to three O atoms. There are a spread of Ba–O bond distances ranging from 2.60–2.62 Å. In the fifth Ba site, Ba is bonded in a 3-coordinate geometry to three O atoms. There are a spread of Ba–O bond distances ranging from 2.62–2.65 Å. There are eight inequivalent Al sites. In the first Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There is three shorter (1.75 Å) and one longer (1.76 Å) Al–O bond length. In the second Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.74–1.76 Å. In the third Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.75–1.77 Å. In the fourth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There is three shorter (1.75 Å) and one longer (1.76 Å) Al–O bond length. In the fifth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.75–1.77 Å. In the sixth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There is three shorter (1.75 Å) and one longer (1.76 Å) Al–O bond length. In the seventh Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There is three shorter (1.75 Å) and one longer (1.77 Å) Al–O bond length. In the eighth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There is three shorter (1.75 Å) and one longer (1.76 Å) Al–O bond length. There are eight 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 is one shorter (1.57 Å) and three longer (1.69 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 AlO4 tetrahedra and corners with three SiO4 tetrahedra. There is one shorter (1.58 Å) and three longer (1.68 Å) Si–O bond length. 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 1.57–1.69 Å. In the fourth 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 is one shorter (1.58 Å) and three longer (1.68 Å) Si–O bond length. In the fifth 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 1.57–1.69 Å. In the sixth 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 is one shorter (1.58 Å) and three longer (1.68 Å) Si–O bond length. In the seventh 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 1.57–1.69 Å. In the eighth 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 is one shorter (1.58 Å) and three longer (1.68 Å) Si–O bond length. There are thirty-four inequivalent O sites. In the first O site, O is bonded in a linear geometry to one Al and one Si atom. In the second O site, O is bonded in a linear geometry to one Al and one Si atom. In the third O site, O is bonded in a linear geometry to one Al and one Si atom. 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 linear geometry to one Al and one Si atom. In the seventh O site, O is bonded in a linear geometry to one Al and one Si atom. In the eighth O site, O is bonded in a linear geometry to one Al and one Si atom. In the ninth O site, O is bonded in a distorted trigonal planar geometry to one Ba and two equivalent Al atoms. In the tenth O site, O is bonded in a distorted trigonal planar geometry to one Ba and two Al atoms. In the eleventh O site, O is bonded in a 3-coordinate geometry to one Ba and two equivalent Al atoms. In the twelfth O site, O is bonded in a distorted trigonal planar geometry to one Ba and two Al atoms. In the thirteenth O site, O is bonded in a 2-coordinate geometry to one Ba and two Al atoms. In the fourteenth O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent Si atoms. In the fifteenth O site, O is bonded in a distorted bent 150 degrees geometry to two Si atoms. In the sixteenth O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent Si atoms. In the seventeenth O site, O is bonded in a distorted bent 120 degrees geometry to two Si atoms. In the eighteenth O site, O is bonded in a distorted bent 150 degrees geometry to two Si atoms. In the nineteenth O site, O is bonded in a distorted bent 120 degrees geometry to two Si atoms. In the twentieth O site, O is bonded in a distorted bent 150 degrees geometry to two Si atoms. In the twenty-first O site, O is bonded in a distorted bent 120 degrees geometry to two Si atoms. In the twenty-second O site, O is bonded in a distorted bent 150 degrees geometry to two Si atoms. In the twenty-third O site, O is bonded in a distorted bent 120 degrees geometry to two Si atoms. In the twenty-fourth O site, O is bonded in a distorted bent 150 degrees geometry to two Si atoms. In the twenty-fifth O site, O is bonded in a distorted bent 120 degrees geometry to two Si atoms. In the twenty-sixth O site, O is bonded in a distorted bent 150 degrees geometry to two Si atoms. In the twenty-seventh O site, O is bonded in a distorted trigonal planar geometry to one Ba and two Al atoms. In the twenty-eighth O site, O is bonded in a 3-coordinate geometry to one Ba and two Al atoms. In the twenty-ninth O site, O is bonded in a distorted trigonal planar geometry to one Ba and two Al atoms. In the thirtieth O site, O is bonded in a 3-coordinate geometry to one Ba and two Al atoms. In the thirty-first O site, O is bonded in a distorted trigonal planar geometry to one Ba and two Al atoms. In the thirty-second O site, O is bonded in a 3-coordinate geometry to one Ba and two Al atoms. In the thirty-third O site, O is bonded in a distorted trigonal planar geometry to one Ba and two Al atoms. In the thirty-fourth O site, O is bonded in a 2-coordinate geometry to one Ba and two Al atoms.