Li7TaO6 crystallizes in the trigonal R3 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1) and three equivalent O(2) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Li(3)O6 octahedra, corners with two equivalent Ta(1)O6 octahedra, corners with six equivalent Li(1)O4 tetrahedra,  an edgeedge with one Li(3)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and edges with three equivalent Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 21-66°. In the second Li site, Li(2) is bonded to one O(2) and three equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(3)O6 octahedra, corners with two equivalent Ta(1)O6 octahedra, corners with six equivalent Li(2)O4 tetrahedra,  an edgeedge with one Li(3)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and edges with three equivalent Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 26-55°. In the third Li site, Li(3) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted LiO6 octahedra that share corners with six equivalent Li(1)O4 tetrahedra, corners with six equivalent Li(2)O4 tetrahedra, edges with three equivalent Ta(1)O6 octahedra, edges with three equivalent Li(1)O4 tetrahedra, and edges with three equivalent Li(2)O4 tetrahedra. Ta(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form TaO6 octahedra that share corners with six equivalent Li(1)O4 tetrahedra, corners with six equivalent Li(2)O4 tetrahedra, edges with three equivalent Li(3)O6 octahedra, edges with three equivalent Li(1)O4 tetrahedra, and edges with three equivalent Li(2)O4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(3), three equivalent Li(2), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing OLi5Ta pentagonal pyramids. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Li(2), one Li(3), three equivalent Li(1), and one Ta(1) atom.
Li7TaO6 crystallizes in the trigonal R3 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1) and three equivalent O(2) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Li(3)O6 octahedra, corners with two equivalent Ta(1)O6 octahedra, corners with six equivalent Li(1)O4 tetrahedra,  an edgeedge with one Li(3)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and edges with three equivalent Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 21-66°. The Li(1)-O(1) bond length is 2.04 Å. There are a spread of Li(1)-O(2) bond distances ranging from 1.89-2.03 Å. In the second Li site, Li(2) is bonded to one O(2) and three equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(3)O6 octahedra, corners with two equivalent Ta(1)O6 octahedra, corners with six equivalent Li(2)O4 tetrahedra,  an edgeedge with one Li(3)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and edges with three equivalent Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 26-55°. The Li(2)-O(2) bond length is 2.02 Å. There are a spread of Li(2)-O(1) bond distances ranging from 1.97-1.99 Å. In the third Li site, Li(3) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted LiO6 octahedra that share corners with six equivalent Li(1)O4 tetrahedra, corners with six equivalent Li(2)O4 tetrahedra, edges with three equivalent Ta(1)O6 octahedra, edges with three equivalent Li(1)O4 tetrahedra, and edges with three equivalent Li(2)O4 tetrahedra. All Li(3)-O(1) bond lengths are 2.11 Å. All Li(3)-O(2) bond lengths are 2.41 Å. Ta(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form TaO6 octahedra that share corners with six equivalent Li(1)O4 tetrahedra, corners with six equivalent Li(2)O4 tetrahedra, edges with three equivalent Li(3)O6 octahedra, edges with three equivalent Li(1)O4 tetrahedra, and edges with three equivalent Li(2)O4 tetrahedra. All Ta(1)-O(1) bond lengths are 2.05 Å. All Ta(1)-O(2) bond lengths are 2.01 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(3), three equivalent Li(2), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing OLi5Ta pentagonal pyramids. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Li(2), one Li(3), three equivalent Li(1), and one Ta(1) atom.