Materials Data on Na2CoP2O7 by Materials Project

Abstract

Na2CoP2O7 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Na–O bond distances ranging from 2.54–2.94 Å. In the second Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.21–2.69 Å. Co2+ is bonded to five O2- atoms to form CoO5 trigonal bipyramids that share corners with five PO4 tetrahedra. There are a spread of Co–O bond distances ranging from 2.00–2.11 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 a cornercorner with one PO4 tetrahedra and corners with three equivalent CoO5 trigonal bipyramids. There are a spread of P–O bond distances ranging from 1.53–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one PO4 tetrahedra and corners with two equivalent CoO5 trigonal bipyramids. There are a spread of P–O bond distances ranging from 1.50–1.66 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+, one Co2+, and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Co2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Co2+, and one P5+ atom.