Materials Data on Er3O2F5 by Materials Project
Er3O2F5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded in a 7-coordinate geometry to two equivalent O2- and five F1- atoms. There are one shorter (2.19 Å) and one longer (2.22 Å) Er–O bond lengths. There are a spread of Er–F bond distances ranging from 2.21–2.38 Å. In the second Er3+ site, Er3+ is bonded in a 8-coordinate geometry to four equivalent O2- and four F1- atoms. There are two shorter (2.26 Å) and two longer (2.32 Å) Er–O bond lengths. There are a spread of Er–F bond distances ranging from 2.26–2.50 Å. O2- is bonded to four Er3+ atoms to form a mixture of distorted edge and corner-sharing OEr4 tetrahedra. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Er3+ atoms. In the second F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Er3+ atoms. In the third F1- site, F1- is bonded in a 3-coordinate geometry to three Er3+ atoms.