NaLiEr2F8 crystallizes in the orthorhombic Cmcm space group. Na(1) is bonded in a 7-coordinate geometry to one F(3), two equivalent F(4), and four equivalent F(2) atoms. Li(1) is bonded to two equivalent F(1) and four equivalent F(2) atoms to form distorted corner-sharing LiF6 octahedra. The corner-sharing octahedral tilt angles are 45°. Er(1) is bonded in a 8-coordinate geometry to one F(1), one F(3), two equivalent F(4), and four equivalent F(2) atoms. There are four inequivalent F sites. In the first F site, F(1) is bonded to two equivalent Li(1) and two equivalent Er(1) atoms to form distorted FLi2Er2 tetrahedra that share corners with two equivalent F(1)Li2Er2 tetrahedra, corners with eight equivalent F(2)NaLiEr2 trigonal pyramids, and edges with four equivalent F(2)NaLiEr2 trigonal pyramids. In the second F site, F(2) is bonded to one Na(1), one Li(1), and two equivalent Er(1) atoms to form distorted FNaLiEr2 trigonal pyramids that share corners with two equivalent F(1)Li2Er2 tetrahedra, corners with six equivalent F(2)NaLiEr2 trigonal pyramids,  an edgeedge with one F(1)Li2Er2 tetrahedra, and edges with three equivalent F(2)NaLiEr2 trigonal pyramids. In the third F site, F(3) is bonded in a trigonal planar geometry to one Na(1) and two equivalent Er(1) atoms. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Na(1) and two equivalent Er(1) atoms.
NaLiEr2F8 crystallizes in the orthorhombic Cmcm space group. Na(1) is bonded in a 7-coordinate geometry to one F(3), two equivalent F(4), and four equivalent F(2) atoms. The Na(1)-F(3) bond length is 2.23 Å. Both Na(1)-F(4) bond lengths are 2.55 Å. All Na(1)-F(2) bond lengths are 2.35 Å. Li(1) is bonded to two equivalent F(1) and four equivalent F(2) atoms to form distorted corner-sharing LiF6 octahedra. The corner-sharing octahedral tilt angles are 45°. Both Li(1)-F(1) bond lengths are 1.92 Å. All Li(1)-F(2) bond lengths are 2.27 Å. Er(1) is bonded in a 8-coordinate geometry to one F(1), one F(3), two equivalent F(4), and four equivalent F(2) atoms. The Er(1)-F(1) bond length is 2.45 Å. The Er(1)-F(3) bond length is 2.23 Å. There is one shorter (2.21 Å) and one longer (2.22 Å) Er(1)-F(4) bond length. There are two shorter (2.24 Å) and two longer (2.33 Å) Er(1)-F(2) bond lengths. There are four inequivalent F sites. In the first F site, F(1) is bonded to two equivalent Li(1) and two equivalent Er(1) atoms to form distorted FLi2Er2 tetrahedra that share corners with two equivalent F(1)Li2Er2 tetrahedra, corners with eight equivalent F(2)NaLiEr2 trigonal pyramids, and edges with four equivalent F(2)NaLiEr2 trigonal pyramids. In the second F site, F(2) is bonded to one Na(1), one Li(1), and two equivalent Er(1) atoms to form distorted FNaLiEr2 trigonal pyramids that share corners with two equivalent F(1)Li2Er2 tetrahedra, corners with six equivalent F(2)NaLiEr2 trigonal pyramids,  an edgeedge with one F(1)Li2Er2 tetrahedra, and edges with three equivalent F(2)NaLiEr2 trigonal pyramids. In the third F site, F(3) is bonded in a trigonal planar geometry to one Na(1) and two equivalent Er(1) atoms. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Na(1) and two equivalent Er(1) atoms.