Materials Data on SnAs2O9 by Materials Project
SnAs2O7O2 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four hydrogen peroxide molecules and two SnAs2O7 sheets oriented in the (0, 0, 1) direction. In each SnAs2O7 sheet, Sn is bonded to six O atoms to form SnO6 octahedra that share corners with five AsO4 tetrahedra and an edgeedge with one AsO4 tetrahedra. There are a spread of Sn–O bond distances ranging from 2.02–2.38 Å. There are two inequivalent As sites. In the first As site, As is bonded to four O atoms to form AsO4 tetrahedra that share corners with two equivalent SnO6 octahedra, a cornercorner with one AsO4 tetrahedra, and an edgeedge with one SnO6 octahedra. The corner-sharing octahedra tilt angles range from 37–61°. There are a spread of As–O bond distances ranging from 1.70–1.82 Å. In the second As site, As is bonded to four O atoms to form AsO4 tetrahedra that share corners with three equivalent SnO6 octahedra and a cornercorner with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–51°. There are a spread of As–O bond distances ranging from 1.63–1.93 Å. There are seven inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to one Sn and one As atom. In the second O site, O is bonded in a bent 120 degrees geometry to one Sn and one As atom. In the third O site, O is bonded in a single-bond geometry to one As atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to one Sn and one As atom. In the fifth O site, O is bonded in a water-like geometry to one Sn and one As atom. In the sixth O site, O is bonded in a bent 120 degrees geometry to one Sn and one As atom. In the seventh O site, O is bonded in a 3-coordinate geometry to one Sn and two As atoms.