Materials Data on BeCuO5F4 by Materials Project

Abstract

Be2Cu(O3F4)2CuO4 crystallizes in the triclinic P-1 space group. The structure is one-dimensional and consists of one CuO4 cluster and one Be2Cu(O3F4)2 ribbon oriented in the (1, 0, 0) direction. In the CuO4 cluster, Cu is bonded in a square co-planar geometry to four O atoms. There is two shorter (1.77 Å) and two longer (1.84 Å) Cu–O bond length. There are two inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Cu atom. In the second O site, O is bonded in a single-bond geometry to one Cu atom. In the Be2Cu(O3F4)2 ribbon, Be is bonded to four F atoms to form BeF4 tetrahedra that share corners with two equivalent CuO2F4 octahedra. The corner-sharing octahedra tilt angles range from 20–55°. There are a spread of Be–F bond distances ranging from 1.51–1.69 Å. Cu is bonded to two equivalent O and four F atoms to form distorted CuO2F4 octahedra that share corners with four equivalent BeF4 tetrahedra. Both Cu–O bond lengths are 1.82 Å. There are two shorter (1.84 Å) and two longer (2.33 Å) Cu–F bond lengths. There are three inequivalent O sites. In the first O site, O is bonded in a distorted water-like geometry to two O atoms. There is one shorter (1.21 Å) and one longer (1.85 Å) O–O bond length. In the second O site, O is bonded in a single-bond geometry to one Cu and one O atom. In the third O site, O is bonded in a single-bond geometry to one O atom. There are four inequivalent F sites. In the first F site, F is bonded in a bent 120 degrees geometry to one Be and one Cu atom. In the second F site, F is bonded in a single-bond geometry to one Be atom. In the third F site, F is bonded in a single-bond geometry to one Be atom. In the fourth F site, F is bonded in a distorted single-bond geometry to one Be and one Cu atom.