DOI: 10.17188/1742418
title: Materials Data on CaP2H5NO7 by Materials Project

description: Ca(NH4)HP2O7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional and consists of eight ammonium molecules and one CaP2HO7 framework. In the CaP2HO7 framework, there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to seven O2- atoms to form CaO7 pentagonal bipyramids that share a cornercorner with one CaO7 pentagonal bipyramid, corners with five PO4 tetrahedra, edges with two equivalent CaO7 pentagonal bipyramids, and an edgeedge with one PO4 tetrahedra. There are a spread of Ca–O bond distances ranging from 2.33–2.68 Å. In the second Ca2+ site, Ca2+ is bonded to seven O2- atoms to form distorted CaO7 pentagonal bipyramids that share a cornercorner with one CaO7 pentagonal bipyramid, corners with five PO4 tetrahedra, edges with two equivalent CaO7 pentagonal bipyramids, and an edgeedge with one PO4 tetrahedra. There are a spread of Ca–O bond distances ranging from 2.29–2.69 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two CaO7 pentagonal bipyramids and a cornercorner with one PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.52–1.64 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two CaO7 pentagonal bipyramids and a cornercorner with one PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two CaO7 pentagonal bipyramids, a cornercorner with one PO4 tetrahedra, and edges with two CaO7 pentagonal bipyramids. There are a spread of P–O bond distances ranging from 1.53–1.63 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four CaO7 pentagonal bipyramids and a cornercorner with one PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.51–1.63 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.64 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.09 Å) and one longer (1.37 Å) H–O bond length. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one P5+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ca2+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one P5+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two Ca2+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ca2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Ca2+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to one P5+ and one H1+ atom. In the eleventh O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ca2+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Ca2+ and one P5+ atom.