Li3TaO4 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form LiO6 octahedra that share  a cornercorner with one Li(3)O6 octahedra,  a cornercorner with one Ta(1)O6 octahedra, corners with four equivalent Li(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-12°. In the second Li site, Li(2) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form LiO6 octahedra that share  a cornercorner with one Li(3)O6 octahedra,  a cornercorner with one Ta(1)O6 octahedra, corners with four equivalent Li(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-14°. In the third Li site, Li(3) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted LiO6 octahedra that share  a cornercorner with one Li(1)O6 octahedra,  a cornercorner with one Li(2)O6 octahedra, corners with four equivalent Ta(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Ta(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-12°. Ta(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form TaO6 octahedra that share  a cornercorner with one Li(1)O6 octahedra,  a cornercorner with one Li(2)O6 octahedra, corners with four equivalent Li(3)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Ta(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), one Li(3), two equivalent Li(1), and two equivalent Ta(1) atoms to form OLi4Ta2 octahedra that share  a cornercorner with one O(2)Li4Ta2 octahedra,  a cornercorner with one O(4)Li5Ta octahedra, corners with four equivalent O(3)Li5Ta octahedra, edges with two equivalent O(1)Li4Ta2 octahedra, edges with two equivalent O(3)Li5Ta octahedra, edges with four equivalent O(2)Li4Ta2 octahedra, and edges with four equivalent O(4)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 3-17°. In the second O site, O(2) is bonded to one Li(1), one Li(3), two equivalent Li(2), and two equivalent Ta(1) atoms to form OLi4Ta2 octahedra that share  a cornercorner with one O(1)Li4Ta2 octahedra,  a cornercorner with one O(3)Li5Ta octahedra, corners with four equivalent O(4)Li5Ta octahedra, edges with two equivalent O(2)Li4Ta2 octahedra, edges with two equivalent O(4)Li5Ta octahedra, edges with four equivalent O(1)Li4Ta2 octahedra, and edges with four equivalent O(3)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 1-17°. In the third O site, O(3) is bonded to one Li(1), two equivalent Li(2), two equivalent Li(3), and one Ta(1) atom to form OLi5Ta octahedra that share  a cornercorner with one O(2)Li4Ta2 octahedra,  a cornercorner with one O(4)Li5Ta octahedra, corners with four equivalent O(1)Li4Ta2 octahedra, edges with two equivalent O(1)Li4Ta2 octahedra, edges with two equivalent O(3)Li5Ta octahedra, edges with four equivalent O(2)Li4Ta2 octahedra, and edges with four equivalent O(4)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 3-18°. In the fourth O site, O(4) is bonded to one Li(2), two equivalent Li(1), two equivalent Li(3), and one Ta(1) atom to form OLi5Ta octahedra that share  a cornercorner with one O(1)Li4Ta2 octahedra,  a cornercorner with one O(3)Li5Ta octahedra, corners with four equivalent O(2)Li4Ta2 octahedra, edges with two equivalent O(2)Li4Ta2 octahedra, edges with two equivalent O(4)Li5Ta octahedra, edges with four equivalent O(1)Li4Ta2 octahedra, and edges with four equivalent O(3)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 1-18°.
Li3TaO4 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form LiO6 octahedra that share  a cornercorner with one Li(3)O6 octahedra,  a cornercorner with one Ta(1)O6 octahedra, corners with four equivalent Li(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-12°. The Li(1)-O(2) bond length is 2.10 Å. The Li(1)-O(3) bond length is 2.12 Å. There is one shorter (2.07 Å) and one longer (2.13 Å) Li(1)-O(1) bond length. There is one shorter (2.13 Å) and one longer (2.22 Å) Li(1)-O(4) bond length. In the second Li site, Li(2) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form LiO6 octahedra that share  a cornercorner with one Li(3)O6 octahedra,  a cornercorner with one Ta(1)O6 octahedra, corners with four equivalent Li(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-14°. The Li(2)-O(1) bond length is 2.17 Å. The Li(2)-O(4) bond length is 2.08 Å. There is one shorter (2.08 Å) and one longer (2.19 Å) Li(2)-O(2) bond length. There is one shorter (2.08 Å) and one longer (2.21 Å) Li(2)-O(3) bond length. In the third Li site, Li(3) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted LiO6 octahedra that share  a cornercorner with one Li(1)O6 octahedra,  a cornercorner with one Li(2)O6 octahedra, corners with four equivalent Ta(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Ta(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-12°. The Li(3)-O(1) bond length is 2.43 Å. The Li(3)-O(2) bond length is 2.43 Å. There is one shorter (2.03 Å) and one longer (2.05 Å) Li(3)-O(3) bond length. There is one shorter (2.03 Å) and one longer (2.04 Å) Li(3)-O(4) bond length. Ta(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form TaO6 octahedra that share  a cornercorner with one Li(1)O6 octahedra,  a cornercorner with one Li(2)O6 octahedra, corners with four equivalent Li(3)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Ta(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. The Ta(1)-O(3) bond length is 1.89 Å. The Ta(1)-O(4) bond length is 1.89 Å. There is one shorter (1.99 Å) and one longer (2.14 Å) Ta(1)-O(1) bond length. There is one shorter (1.99 Å) and one longer (2.14 Å) Ta(1)-O(2) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), one Li(3), two equivalent Li(1), and two equivalent Ta(1) atoms to form OLi4Ta2 octahedra that share  a cornercorner with one O(2)Li4Ta2 octahedra,  a cornercorner with one O(4)Li5Ta octahedra, corners with four equivalent O(3)Li5Ta octahedra, edges with two equivalent O(1)Li4Ta2 octahedra, edges with two equivalent O(3)Li5Ta octahedra, edges with four equivalent O(2)Li4Ta2 octahedra, and edges with four equivalent O(4)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 3-17°. In the second O site, O(2) is bonded to one Li(1), one Li(3), two equivalent Li(2), and two equivalent Ta(1) atoms to form OLi4Ta2 octahedra that share  a cornercorner with one O(1)Li4Ta2 octahedra,  a cornercorner with one O(3)Li5Ta octahedra, corners with four equivalent O(4)Li5Ta octahedra, edges with two equivalent O(2)Li4Ta2 octahedra, edges with two equivalent O(4)Li5Ta octahedra, edges with four equivalent O(1)Li4Ta2 octahedra, and edges with four equivalent O(3)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 1-17°. In the third O site, O(3) is bonded to one Li(1), two equivalent Li(2), two equivalent Li(3), and one Ta(1) atom to form OLi5Ta octahedra that share  a cornercorner with one O(2)Li4Ta2 octahedra,  a cornercorner with one O(4)Li5Ta octahedra, corners with four equivalent O(1)Li4Ta2 octahedra, edges with two equivalent O(1)Li4Ta2 octahedra, edges with two equivalent O(3)Li5Ta octahedra, edges with four equivalent O(2)Li4Ta2 octahedra, and edges with four equivalent O(4)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 3-18°. In the fourth O site, O(4) is bonded to one Li(2), two equivalent Li(1), two equivalent Li(3), and one Ta(1) atom to form OLi5Ta octahedra that share  a cornercorner with one O(1)Li4Ta2 octahedra,  a cornercorner with one O(3)Li5Ta octahedra, corners with four equivalent O(2)Li4Ta2 octahedra, edges with two equivalent O(2)Li4Ta2 octahedra, edges with two equivalent O(4)Li5Ta octahedra, edges with four equivalent O(1)Li4Ta2 octahedra, and edges with four equivalent O(3)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 1-18°.