Materials Data on Fe2AsO4F by Materials Project

Abstract

Fe2(AsO4)F crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are four inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- and two F1- atoms to form distorted FeO4F2 pentagonal pyramids that share corners with four AsO4 tetrahedra, corners with two FeO4F trigonal bipyramids, edges with two equivalent FeO4F2 octahedra, and an edgeedge with one FeO4F trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 2.13–2.16 Å. There are one shorter (2.17 Å) and one longer (2.31 Å) Fe–F bond lengths. In the second Fe3+ site, Fe3+ is bonded to four O2- and one F1- atom to form FeO4F trigonal bipyramids that share a cornercorner with one FeO4F2 octahedra, a cornercorner with one FeO4F2 pentagonal pyramid, corners with four AsO4 tetrahedra, corners with two equivalent FeO4F trigonal bipyramids, and an edgeedge with one FeO4F2 pentagonal pyramid. The corner-sharing octahedral tilt angles are 53°. There are a spread of Fe–O bond distances ranging from 2.11–2.17 Å. The Fe–F bond length is 2.01 Å. In the third Fe3+ site, Fe3+ is bonded to four O2- and two F1- atoms to form FeO4F2 octahedra that share corners with four AsO4 tetrahedra, corners with two FeO4F trigonal bipyramids, edges with two equivalent FeO4F2 pentagonal pyramids, and an edgeedge with one FeO4F trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 2.10–2.18 Å. There are one shorter (2.16 Å) and one longer (2.19 Å) Fe–F bond lengths. In the fourth Fe3+ site, Fe3+ is bonded to four O2- and one F1- atom to form FeO4F trigonal bipyramids that share a cornercorner with one FeO4F2 octahedra, a cornercorner with one FeO4F2 pentagonal pyramid, corners with four AsO4 tetrahedra, corners with two equivalent FeO4F trigonal bipyramids, and an edgeedge with one FeO4F2 octahedra. The corner-sharing octahedral tilt angles are 51°. There are two shorter (2.10 Å) and two longer (2.12 Å) Fe–O bond lengths. The Fe–F bond length is 2.04 Å. There are two inequivalent As3+ sites. In the first As3+ site, As3+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent FeO4F2 octahedra, corners with two equivalent FeO4F2 pentagonal pyramids, and corners with four FeO4F trigonal bipyramids. The corner-sharing octahedra tilt angles range from 48–56°. There is one shorter (1.71 Å) and three longer (1.73 Å) As–O bond length. In the second As3+ site, As3+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent FeO4F2 octahedra, corners with two equivalent FeO4F2 pentagonal pyramids, and corners with four FeO4F trigonal bipyramids. The corner-sharing octahedra tilt angles range from 47–59°. There is two shorter (1.72 Å) and two longer (1.73 Å) As–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe3+ and one As3+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe3+ and one As3+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe3+ and one As3+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe3+ and one As3+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe3+ and one As3+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe3+ and one As3+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe3+ and one As3+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe3+ and one As3+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 3-coordinate geometry to three Fe3+ atoms. In the second F1- site, F1- is bonded in a distorted trigonal planar geometry to three Fe3+ atoms.