Li2Co2Si2O7 crystallizes in the orthorhombic Ama2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(3) atoms. In the second Li site, Li(2) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted LiO5 square pyramids that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Co(1)O4 trigonal pyramids, and edges with two equivalent Si(1)O4 tetrahedra. Co(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form distorted CoO4 trigonal pyramids that share corners with two equivalent Li(2)O5 square pyramids, corners with four equivalent Si(1)O4 tetrahedra, and corners with two equivalent Co(1)O4 trigonal pyramids. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra, corners with four equivalent Co(1)O4 trigonal pyramids, and  an edgeedge with one Li(2)O5 square pyramid. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one Si(1) atom. In the second O site, O(1) is bonded in a distorted T-shaped geometry to one Li(2) and two equivalent Si(1) atoms. In the third O site, O(2) is bonded to one Li(1), one Li(2), one Co(1), and one Si(1) atom to form distorted corner-sharing OLi2CoSi tetrahedra. In the fourth O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one Co(1), and one Si(1) atom.
Li2Co2Si2O7 crystallizes in the orthorhombic Ama2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(3) atoms. Both Li(1)-O(2) bond lengths are 2.20 Å. Both Li(1)-O(3) bond lengths are 2.25 Å. In the second Li site, Li(2) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted LiO5 square pyramids that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Co(1)O4 trigonal pyramids, and edges with two equivalent Si(1)O4 tetrahedra. The Li(2)-O(1) bond length is 2.31 Å. Both Li(2)-O(2) bond lengths are 2.23 Å. Both Li(2)-O(3) bond lengths are 2.21 Å. Co(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form distorted CoO4 trigonal pyramids that share corners with two equivalent Li(2)O5 square pyramids, corners with four equivalent Si(1)O4 tetrahedra, and corners with two equivalent Co(1)O4 trigonal pyramids. The Co(1)-O(2) bond length is 2.01 Å. The Co(1)-O(3) bond length is 1.93 Å. There is one shorter (1.99 Å) and one longer (2.00 Å) Co(1)-O(4) bond length. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra, corners with four equivalent Co(1)O4 trigonal pyramids, and  an edgeedge with one Li(2)O5 square pyramid. The Si(1)-O(1) bond length is 1.66 Å. The Si(1)-O(2) bond length is 1.63 Å. The Si(1)-O(3) bond length is 1.63 Å. The Si(1)-O(4) bond length is 1.65 Å. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one Si(1) atom. In the second O site, O(1) is bonded in a distorted T-shaped geometry to one Li(2) and two equivalent Si(1) atoms. In the third O site, O(2) is bonded to one Li(1), one Li(2), one Co(1), and one Si(1) atom to form distorted corner-sharing OLi2CoSi tetrahedra. In the fourth O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one Co(1), and one Si(1) atom.