LiY3(SiO4)2F2 crystallizes in the monoclinic C2/c space group. Li(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent F(1) atoms. In the second Y site, Y(2) is bonded in a 7-coordinate geometry to one O(1), one O(4), two equivalent O(2), two equivalent O(3), and one F(1) atom. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Y(2) and one Si(1) atom. In the second O site, O(4) is bonded to one Li(1), one Y(1), one Y(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiY2Si trigonal pyramids. In the third O site, O(1) is bonded to one Li(1), one Y(1), one Y(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiY2Si tetrahedra. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Y(1), two equivalent Y(2), and one Si(1) atom. F(1) is bonded in a distorted bent 150 degrees geometry to one Y(1) and one Y(2) atom.
LiY3(SiO4)2F2 crystallizes in the monoclinic C2/c space group. Li(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. Both Li(1)-O(1) bond lengths are 2.18 Å. Both Li(1)-O(4) bond lengths are 2.16 Å. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent F(1) atoms. Both Y(1)-O(1) bond lengths are 2.39 Å. Both Y(1)-O(2) bond lengths are 2.32 Å. Both Y(1)-O(4) bond lengths are 2.50 Å. Both Y(1)-F(1) bond lengths are 2.25 Å. In the second Y site, Y(2) is bonded in a 7-coordinate geometry to one O(1), one O(4), two equivalent O(2), two equivalent O(3), and one F(1) atom. The Y(2)-O(1) bond length is 2.49 Å. The Y(2)-O(4) bond length is 2.31 Å. There is one shorter (2.38 Å) and one longer (2.45 Å) Y(2)-O(2) bond length. There is one shorter (2.29 Å) and one longer (2.34 Å) Y(2)-O(3) bond length. The Y(2)-F(1) bond length is 2.24 Å. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Si(1)-O(1) bond length is 1.64 Å. The Si(1)-O(2) bond length is 1.67 Å. The Si(1)-O(3) bond length is 1.65 Å. The Si(1)-O(4) bond length is 1.66 Å. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Y(2) and one Si(1) atom. In the second O site, O(4) is bonded to one Li(1), one Y(1), one Y(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiY2Si trigonal pyramids. In the third O site, O(1) is bonded to one Li(1), one Y(1), one Y(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiY2Si tetrahedra. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Y(1), two equivalent Y(2), and one Si(1) atom. F(1) is bonded in a distorted bent 150 degrees geometry to one Y(1) and one Y(2) atom.