Li2Co2Si2O7 is Chalcostibite-derived structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted trigonal non-coplanar geometry to one O(4), one O(5), and one O(7) atom. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(6), one O(7), and two equivalent O(3) atoms. In the second Co site, Co(2) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form CoO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra and corners with two equivalent Co(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Co(2)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Li(2), one Co(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Li(2), one Co(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Co(2), two equivalent Co(1), and one Si(1) atom to form distorted OCo3Si tetrahedra that share  a cornercorner with one O(4)Li2CoSi tetrahedra,  a cornercorner with one O(5)Li2CoSi tetrahedra, corners with two equivalent O(7)LiCo2Si tetrahedra,  an edgeedge with one O(3)Co3Si tetrahedra, and  an edgeedge with one O(7)LiCo2Si tetrahedra. In the fourth O site, O(4) is bonded to one Li(1), one Li(2), one Co(2), and one Si(2) atom to form distorted OLi2CoSi tetrahedra that share  a cornercorner with one O(3)Co3Si tetrahedra, corners with two equivalent O(7)LiCo2Si tetrahedra, and corners with four equivalent O(5)Li2CoSi tetrahedra. In the fifth O site, O(5) is bonded to one Li(1), one Li(2), one Co(2), and one Si(2) atom to form OLi2CoSi tetrahedra that share  a cornercorner with one O(3)Co3Si tetrahedra, corners with two equivalent O(7)LiCo2Si tetrahedra, and corners with four equivalent O(4)Li2CoSi tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(2), one Co(1), and one Si(2) atom. In the seventh O site, O(7) is bonded to one Li(1), one Co(1), one Co(2), and one Si(1) atom to form distorted OLiCo2Si tetrahedra that share corners with two equivalent O(3)Co3Si tetrahedra, corners with two equivalent O(4)Li2CoSi tetrahedra, corners with two equivalent O(5)Li2CoSi tetrahedra, and  an edgeedge with one O(3)Co3Si tetrahedra.
Li2Co2Si2O7 is Chalcostibite-derived structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted trigonal non-coplanar geometry to one O(4), one O(5), and one O(7) atom. The Li(1)-O(4) bond length is 2.09 Å. The Li(1)-O(5) bond length is 1.98 Å. The Li(1)-O(7) bond length is 1.98 Å. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. The Li(2)-O(1) bond length is 2.53 Å. The Li(2)-O(2) bond length is 2.01 Å. The Li(2)-O(4) bond length is 2.19 Å. The Li(2)-O(5) bond length is 2.34 Å. The Li(2)-O(6) bond length is 2.08 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(6), one O(7), and two equivalent O(3) atoms. The Co(1)-O(1) bond length is 2.49 Å. The Co(1)-O(2) bond length is 1.99 Å. The Co(1)-O(6) bond length is 1.96 Å. The Co(1)-O(7) bond length is 2.18 Å. There is one shorter (2.10 Å) and one longer (2.30 Å) Co(1)-O(3) bond length. In the second Co site, Co(2) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form CoO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. The Co(2)-O(3) bond length is 2.00 Å. The Co(2)-O(4) bond length is 1.99 Å. The Co(2)-O(5) bond length is 1.98 Å. The Co(2)-O(7) bond length is 2.02 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra and corners with two equivalent Co(2)O4 tetrahedra. The Si(1)-O(1) bond length is 1.67 Å. The Si(1)-O(2) bond length is 1.62 Å. The Si(1)-O(3) bond length is 1.65 Å. The Si(1)-O(7) bond length is 1.65 Å. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Co(2)O4 tetrahedra. The Si(2)-O(1) bond length is 1.68 Å. The Si(2)-O(4) bond length is 1.65 Å. The Si(2)-O(5) bond length is 1.65 Å. The Si(2)-O(6) bond length is 1.62 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Li(2), one Co(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Li(2), one Co(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Co(2), two equivalent Co(1), and one Si(1) atom to form distorted OCo3Si tetrahedra that share  a cornercorner with one O(4)Li2CoSi tetrahedra,  a cornercorner with one O(5)Li2CoSi tetrahedra, corners with two equivalent O(7)LiCo2Si tetrahedra,  an edgeedge with one O(3)Co3Si tetrahedra, and  an edgeedge with one O(7)LiCo2Si tetrahedra. In the fourth O site, O(4) is bonded to one Li(1), one Li(2), one Co(2), and one Si(2) atom to form distorted OLi2CoSi tetrahedra that share  a cornercorner with one O(3)Co3Si tetrahedra, corners with two equivalent O(7)LiCo2Si tetrahedra, and corners with four equivalent O(5)Li2CoSi tetrahedra. In the fifth O site, O(5) is bonded to one Li(1), one Li(2), one Co(2), and one Si(2) atom to form OLi2CoSi tetrahedra that share  a cornercorner with one O(3)Co3Si tetrahedra, corners with two equivalent O(7)LiCo2Si tetrahedra, and corners with four equivalent O(4)Li2CoSi tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(2), one Co(1), and one Si(2) atom. In the seventh O site, O(7) is bonded to one Li(1), one Co(1), one Co(2), and one Si(1) atom to form distorted OLiCo2Si tetrahedra that share corners with two equivalent O(3)Co3Si tetrahedra, corners with two equivalent O(4)Li2CoSi tetrahedra, corners with two equivalent O(5)Li2CoSi tetrahedra, and  an edgeedge with one O(3)Co3Si tetrahedra.