Li2LaTa2O7 crystallizes in the tetragonal I4/mmm space group. Li(1) is bonded to four equivalent O(1) atoms to form distorted LiO4 trigonal pyramids that share corners with four equivalent Ta(1)O6 octahedra, corners with four equivalent Li(1)O4 trigonal pyramids, and edges with four equivalent Li(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles are 72°. La(1) is bonded to four equivalent O(2) and eight equivalent O(3) atoms to form LaO12 cuboctahedra that share corners with four equivalent La(1)O12 cuboctahedra, faces with four equivalent La(1)O12 cuboctahedra, and faces with eight equivalent Ta(1)O6 octahedra. Ta(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form TaO6 octahedra that share corners with five equivalent Ta(1)O6 octahedra, corners with four equivalent Li(1)O4 trigonal pyramids, and faces with four equivalent La(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-17°. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Li(1) and one Ta(1) atom to form a mixture of distorted edge and corner-sharing OLi4Ta trigonal bipyramids. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent La(1) and two equivalent Ta(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent La(1) and two equivalent Ta(1) atoms.
Li2LaTa2O7 crystallizes in the tetragonal I4/mmm space group. Li(1) is bonded to four equivalent O(1) atoms to form distorted LiO4 trigonal pyramids that share corners with four equivalent Ta(1)O6 octahedra, corners with four equivalent Li(1)O4 trigonal pyramids, and edges with four equivalent Li(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles are 72°. All Li(1)-O(1) bond lengths are 2.10 Å. La(1) is bonded to four equivalent O(2) and eight equivalent O(3) atoms to form LaO12 cuboctahedra that share corners with four equivalent La(1)O12 cuboctahedra, faces with four equivalent La(1)O12 cuboctahedra, and faces with eight equivalent Ta(1)O6 octahedra. All La(1)-O(2) bond lengths are 2.83 Å. All La(1)-O(3) bond lengths are 2.69 Å. Ta(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form TaO6 octahedra that share corners with five equivalent Ta(1)O6 octahedra, corners with four equivalent Li(1)O4 trigonal pyramids, and faces with four equivalent La(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-17°. The Ta(1)-O(1) bond length is 1.90 Å. The Ta(1)-O(2) bond length is 2.10 Å. All Ta(1)-O(3) bond lengths are 2.02 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Li(1) and one Ta(1) atom to form a mixture of distorted edge and corner-sharing OLi4Ta trigonal bipyramids. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent La(1) and two equivalent Ta(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent La(1) and two equivalent Ta(1) atoms.