Materials Data on SnAs2O9 by Materials Project

Abstract

(Sn(AsO4)2)2O2 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four water molecules and two Sn(AsO4)2 sheets oriented in the (0, 0, 1) direction. In each Sn(AsO4)2 sheet, Sn is bonded to six O atoms to form SnO6 octahedra that share corners with six AsO4 tetrahedra. There are a spread of Sn–O bond distances ranging from 2.06–2.15 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 three equivalent SnO6 octahedra. The corner-sharing octahedra tilt angles range from 47–50°. There is three shorter (1.72 Å) and one longer (1.76 Å) As–O bond length. In the second As site, As is bonded to four O atoms to form AsO4 tetrahedra that share corners with three equivalent SnO6 octahedra. The corner-sharing octahedra tilt angles range from 45–54°. There is three shorter (1.72 Å) and one longer (1.76 Å) As–O bond length. There are eight 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 distorted bent 150 degrees geometry to one Sn and one As atom. In the third O site, O is bonded in a distorted bent 120 degrees geometry to one Sn and one As atom. In the fourth O site, O is bonded in a bent 120 degrees geometry to one Sn and one As atom. In the fifth O site, O is bonded in a single-bond geometry to 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 bent 120 degrees geometry to one Sn and one As atom. In the eighth O site, O is bonded in a single-bond geometry to one As atom.