Na5Tb4Si4O16F crystallizes in the tetragonal I-4 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), and four equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a distorted q6 geometry to four equivalent O(2), four equivalent O(3), and two equivalent F(1) atoms. Tb(1) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(4), 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 5-coordinate geometry to one Na(1), one Na(2), two equivalent Tb(1), and one Si(1) atom. In the second O site, O(4) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Tb(1), and one Si(1) atom. In the third O site, O(1) is bonded in a 6-coordinate geometry to four equivalent Na(1), one Tb(1), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), two equivalent Tb(1), and one Si(1) atom. F(1) is bonded to two equivalent Na(2) and four equivalent Tb(1) atoms to form corner-sharing FNa2Tb4 octahedra. The corner-sharing octahedra are not tilted.
Na5Tb4Si4O16F crystallizes in the tetragonal I-4 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), and four equivalent O(1) atoms. The Na(1)-O(2) bond length is 2.85 Å. The Na(1)-O(3) bond length is 2.68 Å. The Na(1)-O(4) bond length is 2.38 Å. There are a spread of Na(1)-O(1) bond distances ranging from 2.38-2.84 Å. In the second Na site, Na(2) is bonded in a distorted q6 geometry to four equivalent O(2), four equivalent O(3), and two equivalent F(1) atoms. All Na(2)-O(2) bond lengths are 2.62 Å. All Na(2)-O(3) bond lengths are 2.82 Å. Both Na(2)-F(1) bond lengths are 2.73 Å. Tb(1) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(4), and one F(1) atom. The Tb(1)-O(1) bond length is 2.44 Å. There is one shorter (2.34 Å) and one longer (2.38 Å) Tb(1)-O(2) bond length. There is one shorter (2.29 Å) and one longer (2.37 Å) Tb(1)-O(3) bond length. There is one shorter (2.38 Å) and one longer (2.57 Å) Tb(1)-O(4) bond length. The Tb(1)-F(1) bond length is 2.55 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 1.65 Å. The Si(1)-O(2) bond length is 1.64 Å. The Si(1)-O(3) bond length is 1.64 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 5-coordinate geometry to one Na(1), one Na(2), two equivalent Tb(1), and one Si(1) atom. In the second O site, O(4) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Tb(1), and one Si(1) atom. In the third O site, O(1) is bonded in a 6-coordinate geometry to four equivalent Na(1), one Tb(1), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), two equivalent Tb(1), and one Si(1) atom. F(1) is bonded to two equivalent Na(2) and four equivalent Tb(1) atoms to form corner-sharing FNa2Tb4 octahedra. The corner-sharing octahedra are not tilted.