Li2Cr2Si2O7 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 3-coordinate geometry to one O(4), one O(5), and one O(7) atom. In the second Li site, Li(2) is bonded in a distorted rectangular see-saw-like geometry to one O(2), one O(4), one O(5), and one O(6) atom. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), one O(6), one O(7), and two equivalent O(3) atoms to form distorted CrO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Cr(1)O6 octahedra, and edges with two equivalent Si(1)O4 tetrahedra. In the second Cr site, Cr(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(5), and one O(7) atom. 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 Cr(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and edges with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 59°. 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 corners with two equivalent Cr(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 38-58°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Cr(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one Cr(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Cr(2), two equivalent Cr(1), and one Si(1) atom to form distorted OCr3Si tetrahedra that share  a cornercorner with one O(5)Li2CrSi tetrahedra and  an edgeedge with one O(3)Cr3Si tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Cr(2), and one Si(2) atom. In the fifth O site, O(5) is bonded to one Li(1), one Li(2), one Cr(2), and one Si(2) atom to form corner-sharing OLi2CrSi tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(2), one Cr(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Li(1), one Cr(1), one Cr(2), and one Si(1) atom.
Li2Cr2Si2O7 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 3-coordinate geometry to one O(4), one O(5), and one O(7) atom. The Li(1)-O(4) bond length is 2.29 Å. The Li(1)-O(5) bond length is 2.04 Å. The Li(1)-O(7) bond length is 1.98 Å. In the second Li site, Li(2) is bonded in a distorted rectangular see-saw-like geometry to one O(2), one O(4), one O(5), and one O(6) atom. The Li(2)-O(2) bond length is 2.10 Å. The Li(2)-O(4) bond length is 2.18 Å. The Li(2)-O(5) bond length is 2.15 Å. The Li(2)-O(6) bond length is 2.09 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), one O(6), one O(7), and two equivalent O(3) atoms to form distorted CrO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Cr(1)O6 octahedra, and edges with two equivalent Si(1)O4 tetrahedra. The Cr(1)-O(1) bond length is 2.52 Å. The Cr(1)-O(2) bond length is 2.04 Å. The Cr(1)-O(6) bond length is 2.04 Å. The Cr(1)-O(7) bond length is 2.50 Å. There is one shorter (2.16 Å) and one longer (2.17 Å) Cr(1)-O(3) bond length. In the second Cr site, Cr(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(5), and one O(7) atom. The Cr(2)-O(3) bond length is 2.19 Å. The Cr(2)-O(4) bond length is 2.05 Å. The Cr(2)-O(5) bond length is 2.05 Å. The Cr(2)-O(7) bond length is 2.09 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 Cr(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and edges with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 59°. 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 1.67 Å. The Si(1)-O(7) bond length is 1.64 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 corners with two equivalent Cr(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 38-58°. The Si(2)-O(1) bond length is 1.67 Å. The Si(2)-O(4) bond length is 1.65 Å. The Si(2)-O(5) bond length is 1.66 Å. The Si(2)-O(6) bond length is 1.63 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 Cr(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one Cr(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Cr(2), two equivalent Cr(1), and one Si(1) atom to form distorted OCr3Si tetrahedra that share  a cornercorner with one O(5)Li2CrSi tetrahedra and  an edgeedge with one O(3)Cr3Si tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Cr(2), and one Si(2) atom. In the fifth O site, O(5) is bonded to one Li(1), one Li(2), one Cr(2), and one Si(2) atom to form corner-sharing OLi2CrSi tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(2), one Cr(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Li(1), one Cr(1), one Cr(2), and one Si(1) atom.