Materials Data on Na2CaP2O11 by Materials Project

Abstract

Na2CaP2O11 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are two inequivalent Na sites. In the first Na site, Na is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Na–O bond distances ranging from 2.34–2.84 Å. In the second Na site, Na is bonded to five O atoms to form distorted NaO5 square pyramids that share corners with three PO4 tetrahedra and an edgeedge with one CaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.28–2.80 Å. Ca is bonded to six O atoms to form CaO6 octahedra that share corners with five PO4 tetrahedra and an edgeedge with one NaO5 square pyramid. There are a spread of Ca–O bond distances ranging from 2.29–2.41 Å. There are two inequivalent P sites. In the first P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with three equivalent CaO6 octahedra, a cornercorner with one NaO5 square pyramid, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 39–60°. There are a spread of P–O bond distances ranging from 1.52–1.66 Å. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two equivalent CaO6 octahedra, corners with two equivalent NaO5 square pyramids, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–56°. There are a spread of P–O bond distances ranging from 1.53–1.65 Å. There are eleven inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to one Ca and one P atom. In the second O site, O is bonded in a 2-coordinate geometry to one Na and two P atoms. In the third O site, O is bonded in a distorted bent 150 degrees geometry to one Ca and one P atom. In the fourth O site, O is bonded in a distorted trigonal planar geometry to one Na, one Ca, and one P atom. In the fifth O site, O is bonded in a 3-coordinate geometry to one Na, one Ca, and one P atom. In the sixth O site, O is bonded in a 3-coordinate geometry to two Na and one P atom. In the seventh O site, O is bonded in a 3-coordinate geometry to one Na, one Ca, and one P atom. In the eighth O site, O is bonded in an L-shaped geometry to one Na and one Ca atom. In the ninth O site, O is bonded in a distorted T-shaped geometry to two Na and one O atom. The O–O bond length is 1.24 Å. In the tenth O site, O is bonded in a bent 120 degrees geometry to two Na atoms. In the eleventh O site, O is bonded in a bent 120 degrees geometry to one Na and one O atom.