DOI: 10.17188/1270830
title: Materials Data on Na2CaPO4F by Materials Project

description: Na2CaPO4F crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to four O2- and two F1- atoms. There are a spread of Na–O bond distances ranging from 2.36–2.46 Å. There are one shorter (2.36 Å) and one longer (2.48 Å) Na–F bond lengths. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to four O2- and two F1- atoms. There are a spread of Na–O bond distances ranging from 2.36–2.50 Å. There are one shorter (2.34 Å) and one longer (2.45 Å) Na–F bond lengths. In the third Na1+ site, Na1+ is bonded to four O2- and two F1- atoms to form distorted NaO4F2 octahedra that share a cornercorner with one CaO4F2 octahedra, corners with two equivalent CaO5F2 pentagonal bipyramids, corners with four PO4 tetrahedra, an edgeedge with one CaO4F2 octahedra, and a faceface with one CaO5F2 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 13°. There are a spread of Na–O bond distances ranging from 2.35–2.52 Å. There are one shorter (2.37 Å) and one longer (2.38 Å) Na–F bond lengths. In the fourth Na1+ site, Na1+ is bonded in a 6-coordinate geometry to four O2- and two F1- atoms. There are a spread of Na–O bond distances ranging from 2.38–2.53 Å. There are one shorter (2.45 Å) and one longer (2.54 Å) Na–F bond lengths. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to five O2- and two F1- atoms to form distorted CaO5F2 pentagonal bipyramids that share a cornercorner with one CaO4F2 octahedra, corners with two equivalent NaO4F2 octahedra, corners with three PO4 tetrahedra, an edgeedge with one CaO4F2 octahedra, an edgeedge with one PO4 tetrahedra, and a faceface with one NaO4F2 octahedra. The corner-sharing octahedra tilt angles range from 9–73°. There are a spread of Ca–O bond distances ranging from 2.33–2.59 Å. There are one shorter (2.35 Å) and one longer (2.40 Å) Ca–F bond lengths. In the second Ca2+ site, Ca2+ is bonded to four O2- and two F1- atoms to form distorted CaO4F2 octahedra that share a cornercorner with one NaO4F2 octahedra, a cornercorner with one CaO5F2 pentagonal bipyramid, corners with four PO4 tetrahedra, an edgeedge with one NaO4F2 octahedra, and an edgeedge with one CaO5F2 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 13°. There are a spread of Ca–O bond distances ranging from 2.35–2.40 Å. There are one shorter (2.31 Å) and one longer (2.32 Å) Ca–F bond lengths. 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 CaO4F2 octahedra, corners with three equivalent NaO4F2 octahedra, corners with two equivalent CaO5F2 pentagonal bipyramids, and an edgeedge with one CaO5F2 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 52–69°. There are a spread of P–O bond distances ranging from 1.55–1.57 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one NaO4F2 octahedra, corners with three equivalent CaO4F2 octahedra, and a cornercorner with one CaO5F2 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 46–66°. There is three shorter (1.56 Å) and one longer (1.57 Å) P–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+, one Ca2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+, one Ca2+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+, one Ca2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Ca2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two Ca2+, and one P5+ atom. In the sixth O2- site, O2- is bonded to two Na1+, one Ca2+, and one P5+ atom to form distorted ONa2CaP tetrahedra that share corners with six FNa4Ca2 octahedra. The corner-sharing octahedra tilt angles range from 4–74°. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+, one Ca2+, and one P5+ atom. In the eighth O2- site, O2- is bonded to two Na1+, one Ca2+, and one P5+ atom to form ONa2CaP tetrahedra that share corners with six FNa4Ca2 octahedra. The corner-sharing octahedra tilt angles range from 6–65°. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded to four Na1+ and two Ca2+ atoms to form distorted FNa4Ca2 octahedra that share corners with six ONa2CaP tetrahedra and faces with two equivalent FNa4Ca2 octahedra. In the second F1- site, F1- is bonded to four Na1+ and two Ca2+ atoms to form FNa4Ca2 octahedra that share corners with six ONa2CaP tetrahedra and faces with two equivalent FNa4Ca2 octahedra.