Materials Data on CaCrP2O7 by Materials Project
CaCrP2O7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.33–2.86 Å. Cr2+ is bonded to five O2- atoms to form CrO5 square pyramids that share corners with five PO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 2.06–2.47 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 CrO5 square pyramids and a cornercorner with one PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.52–1.63 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CrO5 square pyramids and a cornercorner with one PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.52–1.61 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Cr2+, and one P5+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Cr2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ca2+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ca2+, one Cr2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Cr2+, and one P5+ atom.