Materials Data on NaErPO4F by Materials Project
NaErPO4F crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded in a 6-coordinate geometry to four O2- and two equivalent F1- atoms. There are two shorter (2.50 Å) and two longer (2.63 Å) Na–O bond lengths. Both Na–F bond lengths are 2.46 Å. Er3+ is bonded in a 8-coordinate geometry to six O2- and two equivalent F1- atoms. There are a spread of Er–O bond distances ranging from 2.28–2.44 Å. There are one shorter (2.26 Å) and one longer (2.28 Å) Er–F bond lengths. P5+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.54 Å) and two longer (1.56 Å) P–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Er3+ and one P5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Er3+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Na1+, one Er3+, and one P5+ atom. F1- is bonded to two equivalent Na1+ and two equivalent Er3+ atoms to form distorted edge-sharing FNa2Er2 tetrahedra.