Li3TaO4 is Caswellsilverite-like structured and crystallizes in the monoclinic P2/c space group. There are six inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms to form LiO6 octahedra that share  a cornercorner with one Li(5)O6 octahedra,  a cornercorner with one Ta(1)O6 octahedra, corners with four equivalent Li(3)O6 octahedra,  an edgeedge with one Li(1)O6 octahedra,  an edgeedge with one Li(3)O6 octahedra,  an edgeedge with one Li(4)O6 octahedra,  an edgeedge with one Li(5)O6 octahedra,  an edgeedge with one Li(6)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, edges with three equivalent Li(2)O6 octahedra, and edges with three 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(2), one O(3), one O(5), one O(6), and two equivalent O(1) atoms to form distorted LiO6 octahedra that share  a cornercorner with one Li(3)O6 octahedra,  a cornercorner with one Li(4)O6 octahedra, corners with four equivalent Ta(1)O6 octahedra,  an edgeedge with one Li(2)O6 octahedra,  an edgeedge with one Li(4)O6 octahedra,  an edgeedge with one Li(5)O6 octahedra,  an edgeedge with one Li(6)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, edges with three equivalent Li(1)O6 octahedra, and edges with three equivalent Li(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-13°. In the third Li site, Li(3) is bonded to one O(1), one O(3), one O(5), one O(6), and two equivalent O(2) atoms to form LiO6 octahedra that share  a cornercorner with one Li(2)O6 octahedra,  a cornercorner with one Ta(2)O6 octahedra, corners with four equivalent Li(1)O6 octahedra,  an edgeedge with one Li(1)O6 octahedra,  an edgeedge with one Li(3)O6 octahedra,  an edgeedge with one Li(4)O6 octahedra,  an edgeedge with one Li(5)O6 octahedra,  an edgeedge with one Li(6)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, edges with three equivalent Li(2)O6 octahedra, and edges with three equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-13°. In the fourth Li site, Li(4) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form LiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Li(6)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(5)O6 octahedra, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-12°. In the fifth Li site, Li(5) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form distorted LiO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Ta(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(4)O6 octahedra, edges with two equivalent Li(6)O6 octahedra, and edges with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-10°. In the sixth Li site, Li(6) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form LiO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Li(4)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(5)O6 octahedra, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-12°. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form TaO6 octahedra that share  a cornercorner with one Li(1)O6 octahedra,  a cornercorner with one Li(6)O6 octahedra, corners with four equivalent Li(2)O6 octahedra,  an edgeedge with one Li(2)O6 octahedra,  an edgeedge with one Li(4)O6 octahedra,  an edgeedge with one Li(5)O6 octahedra,  an edgeedge with one Li(6)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, edges with three equivalent Li(1)O6 octahedra, and edges with three equivalent Li(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-12°. In the second Ta site, Ta(2) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form TaO6 octahedra that share corners with two equivalent Li(3)O6 octahedra, corners with four equivalent Li(5)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(4)O6 octahedra, edges with two equivalent Li(6)O6 octahedra, and edges with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-13°. There are six inequivalent O sites. In the first O site, O(6) is bonded to one Li(2), one Li(3), one Li(4), one Li(5), one Li(6), and one Ta(2) atom to form OLi5Ta octahedra that share  a cornercorner with one O(2)Li4Ta2 octahedra,  a cornercorner with one O(1)Li5Ta octahedra, corners with four equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(2)Li4Ta2 octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(5)Li4Ta2 octahedra, edges with two equivalent O(1)Li5Ta octahedra, edges with two equivalent O(3)Li5Ta octahedra, and edges with two equivalent O(6)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 4-17°. In the second O site, O(1) is bonded to one Li(1), one Li(3), one Li(4), two equivalent Li(2), and one Ta(1) atom to form OLi5Ta octahedra that share  a cornercorner with one O(1)Li5Ta octahedra,  a cornercorner with one O(6)Li5Ta octahedra, corners with four equivalent O(5)Li4Ta2 octahedra,  an edgeedge with one O(5)Li4Ta2 octahedra,  an edgeedge with one O(1)Li5Ta octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(6)Li5Ta octahedra, edges with three equivalent O(2)Li4Ta2 octahedra, and edges with three equivalent O(3)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 3-17°. In the third O site, O(2) is bonded to one Li(1), one Li(2), two equivalent Li(3), one Ta(1), and one Ta(2) atom to form OLi4Ta2 octahedra that share  a cornercorner with one O(2)Li4Ta2 octahedra,  a cornercorner with one O(6)Li5Ta octahedra, corners with four equivalent O(3)Li5Ta octahedra,  an edgeedge with one O(2)Li4Ta2 octahedra,  an edgeedge with one O(3)Li5Ta octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(6)Li5Ta octahedra, edges with three equivalent O(5)Li4Ta2 octahedra, and edges with three equivalent O(1)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 1-18°. In the fourth O site, O(3) is bonded to one Li(2), one Li(3), one Li(5), two equivalent Li(1), and one Ta(1) atom to form OLi5Ta octahedra that share  a cornercorner with one O(4)Li4Ta2 octahedra,  a cornercorner with one O(3)Li5Ta octahedra, corners with four equivalent O(2)Li4Ta2 octahedra,  an edgeedge with one O(2)Li4Ta2 octahedra,  an edgeedge with one O(3)Li5Ta octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(6)Li5Ta octahedra, edges with three equivalent O(5)Li4Ta2 octahedra, and edges with three equivalent O(1)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 1-17°. In the fifth O site, O(4) is bonded to one Li(1), one Li(4), one Li(5), one Li(6), one Ta(1), and one Ta(2) atom to form OLi4Ta2 octahedra that share  a cornercorner with one O(5)Li4Ta2 octahedra,  a cornercorner with one O(3)Li5Ta octahedra, corners with four equivalent O(6)Li5Ta octahedra, edges with two equivalent O(2)Li4Ta2 octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(5)Li4Ta2 octahedra, edges with two equivalent O(1)Li5Ta octahedra, edges with two equivalent O(3)Li5Ta octahedra, and edges with two equivalent O(6)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 3-17°. In the sixth O site, O(5) is bonded to one Li(1), one Li(2), one Li(3), one Li(6), and two equivalent Ta(1) atoms to form OLi4Ta2 octahedra that share  a cornercorner with one O(4)Li4Ta2 octahedra,  a cornercorner with one O(5)Li4Ta2 octahedra, corners with four equivalent O(1)Li5Ta octahedra,  an edgeedge with one O(5)Li4Ta2 octahedra,  an edgeedge with one O(1)Li5Ta octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(6)Li5Ta octahedra, edges with three equivalent O(2)Li4Ta2 octahedra, and edges with three equivalent O(3)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 2-17°.
Li3TaO4 is Caswellsilverite-like structured and crystallizes in the monoclinic P2/c space group. There are six inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms to form LiO6 octahedra that share  a cornercorner with one Li(5)O6 octahedra,  a cornercorner with one Ta(1)O6 octahedra, corners with four equivalent Li(3)O6 octahedra,  an edgeedge with one Li(1)O6 octahedra,  an edgeedge with one Li(3)O6 octahedra,  an edgeedge with one Li(4)O6 octahedra,  an edgeedge with one Li(5)O6 octahedra,  an edgeedge with one Li(6)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, edges with three equivalent Li(2)O6 octahedra, and edges with three equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-12°. The Li(1)-O(1) bond length is 2.13 Å. The Li(1)-O(2) bond length is 2.10 Å. The Li(1)-O(4) bond length is 2.06 Å. The Li(1)-O(5) bond length is 2.12 Å. There is one shorter (2.13 Å) and one longer (2.21 Å) Li(1)-O(3) bond length. In the second Li site, Li(2) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(1) atoms to form distorted LiO6 octahedra that share  a cornercorner with one Li(3)O6 octahedra,  a cornercorner with one Li(4)O6 octahedra, corners with four equivalent Ta(1)O6 octahedra,  an edgeedge with one Li(2)O6 octahedra,  an edgeedge with one Li(4)O6 octahedra,  an edgeedge with one Li(5)O6 octahedra,  an edgeedge with one Li(6)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, edges with three equivalent Li(1)O6 octahedra, and edges with three equivalent Li(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-13°. The Li(2)-O(2) bond length is 2.42 Å. The Li(2)-O(3) bond length is 2.03 Å. The Li(2)-O(5) bond length is 2.41 Å. The Li(2)-O(6) bond length is 2.04 Å. Both Li(2)-O(1) bond lengths are 2.04 Å. In the third Li site, Li(3) is bonded to one O(1), one O(3), one O(5), one O(6), and two equivalent O(2) atoms to form LiO6 octahedra that share  a cornercorner with one Li(2)O6 octahedra,  a cornercorner with one Ta(2)O6 octahedra, corners with four equivalent Li(1)O6 octahedra,  an edgeedge with one Li(1)O6 octahedra,  an edgeedge with one Li(3)O6 octahedra,  an edgeedge with one Li(4)O6 octahedra,  an edgeedge with one Li(5)O6 octahedra,  an edgeedge with one Li(6)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, edges with three equivalent Li(2)O6 octahedra, and edges with three equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-13°. The Li(3)-O(1) bond length is 2.09 Å. The Li(3)-O(3) bond length is 2.07 Å. The Li(3)-O(5) bond length is 2.14 Å. The Li(3)-O(6) bond length is 2.22 Å. There is one shorter (2.07 Å) and one longer (2.18 Å) Li(3)-O(2) bond length. In the fourth Li site, Li(4) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form LiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Li(6)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(5)O6 octahedra, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-12°. Both Li(4)-O(1) bond lengths are 2.11 Å. Both Li(4)-O(4) bond lengths are 2.19 Å. Both Li(4)-O(6) bond lengths are 2.06 Å. In the fifth Li site, Li(5) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form distorted LiO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Ta(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(4)O6 octahedra, edges with two equivalent Li(6)O6 octahedra, and edges with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-10°. Both Li(5)-O(3) bond lengths are 2.03 Å. Both Li(5)-O(4) bond lengths are 2.42 Å. Both Li(5)-O(6) bond lengths are 2.03 Å. In the sixth Li site, Li(6) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form LiO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Li(4)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(5)O6 octahedra, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-12°. Both Li(6)-O(4) bond lengths are 2.08 Å. Both Li(6)-O(5) bond lengths are 2.17 Å. Both Li(6)-O(6) bond lengths are 2.14 Å. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form TaO6 octahedra that share  a cornercorner with one Li(1)O6 octahedra,  a cornercorner with one Li(6)O6 octahedra, corners with four equivalent Li(2)O6 octahedra,  an edgeedge with one Li(2)O6 octahedra,  an edgeedge with one Li(4)O6 octahedra,  an edgeedge with one Li(5)O6 octahedra,  an edgeedge with one Li(6)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, edges with three equivalent Li(1)O6 octahedra, and edges with three equivalent Li(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-12°. The Ta(1)-O(1) bond length is 1.88 Å. The Ta(1)-O(2) bond length is 2.15 Å. The Ta(1)-O(3) bond length is 1.87 Å. The Ta(1)-O(4) bond length is 1.98 Å. There is one shorter (1.98 Å) and one longer (2.14 Å) Ta(1)-O(5) bond length. In the second Ta site, Ta(2) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form TaO6 octahedra that share corners with two equivalent Li(3)O6 octahedra, corners with four equivalent Li(5)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(4)O6 octahedra, edges with two equivalent Li(6)O6 octahedra, and edges with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-13°. Both Ta(2)-O(2) bond lengths are 1.98 Å. Both Ta(2)-O(4) bond lengths are 2.15 Å. Both Ta(2)-O(6) bond lengths are 1.87 Å. There are six inequivalent O sites. In the first O site, O(6) is bonded to one Li(2), one Li(3), one Li(4), one Li(5), one Li(6), and one Ta(2) atom to form OLi5Ta octahedra that share  a cornercorner with one O(2)Li4Ta2 octahedra,  a cornercorner with one O(1)Li5Ta octahedra, corners with four equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(2)Li4Ta2 octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(5)Li4Ta2 octahedra, edges with two equivalent O(1)Li5Ta octahedra, edges with two equivalent O(3)Li5Ta octahedra, and edges with two equivalent O(6)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 4-17°. In the second O site, O(1) is bonded to one Li(1), one Li(3), one Li(4), two equivalent Li(2), and one Ta(1) atom to form OLi5Ta octahedra that share  a cornercorner with one O(1)Li5Ta octahedra,  a cornercorner with one O(6)Li5Ta octahedra, corners with four equivalent O(5)Li4Ta2 octahedra,  an edgeedge with one O(5)Li4Ta2 octahedra,  an edgeedge with one O(1)Li5Ta octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(6)Li5Ta octahedra, edges with three equivalent O(2)Li4Ta2 octahedra, and edges with three equivalent O(3)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 3-17°. In the third O site, O(2) is bonded to one Li(1), one Li(2), two equivalent Li(3), one Ta(1), and one Ta(2) atom to form OLi4Ta2 octahedra that share  a cornercorner with one O(2)Li4Ta2 octahedra,  a cornercorner with one O(6)Li5Ta octahedra, corners with four equivalent O(3)Li5Ta octahedra,  an edgeedge with one O(2)Li4Ta2 octahedra,  an edgeedge with one O(3)Li5Ta octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(6)Li5Ta octahedra, edges with three equivalent O(5)Li4Ta2 octahedra, and edges with three equivalent O(1)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 1-18°. In the fourth O site, O(3) is bonded to one Li(2), one Li(3), one Li(5), two equivalent Li(1), and one Ta(1) atom to form OLi5Ta octahedra that share  a cornercorner with one O(4)Li4Ta2 octahedra,  a cornercorner with one O(3)Li5Ta octahedra, corners with four equivalent O(2)Li4Ta2 octahedra,  an edgeedge with one O(2)Li4Ta2 octahedra,  an edgeedge with one O(3)Li5Ta octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(6)Li5Ta octahedra, edges with three equivalent O(5)Li4Ta2 octahedra, and edges with three equivalent O(1)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 1-17°. In the fifth O site, O(4) is bonded to one Li(1), one Li(4), one Li(5), one Li(6), one Ta(1), and one Ta(2) atom to form OLi4Ta2 octahedra that share  a cornercorner with one O(5)Li4Ta2 octahedra,  a cornercorner with one O(3)Li5Ta octahedra, corners with four equivalent O(6)Li5Ta octahedra, edges with two equivalent O(2)Li4Ta2 octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(5)Li4Ta2 octahedra, edges with two equivalent O(1)Li5Ta octahedra, edges with two equivalent O(3)Li5Ta octahedra, and edges with two equivalent O(6)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 3-17°. In the sixth O site, O(5) is bonded to one Li(1), one Li(2), one Li(3), one Li(6), and two equivalent Ta(1) atoms to form OLi4Ta2 octahedra that share  a cornercorner with one O(4)Li4Ta2 octahedra,  a cornercorner with one O(5)Li4Ta2 octahedra, corners with four equivalent O(1)Li5Ta octahedra,  an edgeedge with one O(5)Li4Ta2 octahedra,  an edgeedge with one O(1)Li5Ta octahedra, edges with two equivalent O(4)Li4Ta2 octahedra, edges with two equivalent O(6)Li5Ta octahedra, edges with three equivalent O(2)Li4Ta2 octahedra, and edges with three equivalent O(3)Li5Ta octahedra. The corner-sharing octahedral tilt angles range from 2-17°.