Materials Data on Ca2P2O7 by Materials Project
Ca2P2O7 crystallizes in the tetragonal P4_1 space group. The structure is three-dimensional. there are four inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.32–2.77 Å. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.39–2.88 Å. In the third Ca2+ site, Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.90 Å. In the fourth Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.38–2.95 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.51–1.63 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There is three shorter (1.53 Å) and one longer (1.64 Å) P–O bond length. In the third P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. 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 corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.64 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ca2+ and two P5+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ca2+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and two P5+ atoms. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one P5+ atom.