NaErPO4F crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent F(1) atoms. Er(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), four equivalent O(1), and two equivalent F(1) atoms. P(1) is bonded in a tetrahedral geometry to one O(2), one O(3), and two equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Er(1) and one P(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Er(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Na(1), one Er(1), and one P(1) atom. F(1) is bonded to two equivalent Na(1) and two equivalent Er(1) atoms to form edge-sharing FNa2Er2 tetrahedra.
NaErPO4F crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent F(1) atoms. Both Na(1)-O(2) bond lengths are 2.50 Å. Both Na(1)-O(3) bond lengths are 2.63 Å. Both Na(1)-F(1) bond lengths are 2.46 Å. Er(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), four equivalent O(1), and two equivalent F(1) atoms. The Er(1)-O(2) bond length is 2.30 Å. The Er(1)-O(3) bond length is 2.37 Å. There are two shorter (2.28 Å) and two longer (2.44 Å) Er(1)-O(1) bond lengths. There is one shorter (2.26 Å) and one longer (2.28 Å) Er(1)-F(1) bond length. P(1) is bonded in a tetrahedral geometry to one O(2), one O(3), and two equivalent O(1) atoms. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.54 Å. Both P(1)-O(1) bond lengths are 1.56 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Er(1) and one P(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Er(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Na(1), one Er(1), and one P(1) atom. F(1) is bonded to two equivalent Na(1) and two equivalent Er(1) atoms to form edge-sharing FNa2Er2 tetrahedra.