Materials Data on Cd2Si(P2O7)2 by Materials Project

Abstract

Cd2Si(P2O7)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Cd2+ is bonded to six O2- atoms to form distorted CdO6 octahedra that share corners with two equivalent CdO6 octahedra, corners with six PO4 tetrahedra, and an edgeedge with one CdO6 octahedra. The corner-sharing octahedral tilt angles are 70°. There are a spread of Cd–O bond distances ranging from 2.11–2.71 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four PO4 tetrahedra. All Si–O bond lengths are 1.65 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent CdO6 octahedra, a cornercorner with one SiO4 tetrahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–55°. There are a spread of P–O bond distances ranging from 1.50–1.64 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent CdO6 octahedra, a cornercorner with one SiO4 tetrahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–59°. There are a spread of P–O bond distances ranging from 1.50–1.61 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cd2+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Cd2+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cd2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Si4+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Si4+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cd2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms.