Li3MnSi2O7 crystallizes in the triclinic P1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and corners with three equivalent Mn(1)O4 trigonal pyramids. In the second Li site, Li(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  a cornercorner with one Mn(1)O4 trigonal pyramid. In the third Li site, Li(3) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and corners with three equivalent Mn(1)O4 trigonal pyramids. Mn(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form distorted MnO4 trigonal pyramids that share  a cornercorner with one Li(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent Li(3)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, corners with three equivalent Li(3)O4 tetrahedra, and corners with two equivalent Mn(1)O4 trigonal pyramids. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with two equivalent Mn(1)O4 trigonal pyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(1), one Mn(1), and one Si(2) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(2), one Li(3), and one Si(1) atom. In the third O site, O(3) is bonded to one Li(1), one Li(3), one Mn(1), and one Si(1) atom to form corner-sharing OLi2MnSi tetrahedra. In the fourth O site, O(4) is bonded to one Li(2), one Li(3), one Mn(1), and one Si(1) atom to form corner-sharing OLi2MnSi tetrahedra. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Li(2), and one Si(2) atom. In the sixth O site, O(6) is bonded in a trigonal non-coplanar geometry to one Li(2), one Si(1), and one Si(2) atom. In the seventh O site, O(7) is bonded to one Li(1), one Li(3), one Mn(1), and one Si(2) atom to form distorted corner-sharing OLi2MnSi tetrahedra.
Li3MnSi2O7 crystallizes in the triclinic P1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and corners with three equivalent Mn(1)O4 trigonal pyramids. The Li(1)-O(1) bond length is 1.97 Å. The Li(1)-O(3) bond length is 2.17 Å. The Li(1)-O(5) bond length is 1.85 Å. The Li(1)-O(7) bond length is 2.04 Å. In the second Li site, Li(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  a cornercorner with one Mn(1)O4 trigonal pyramid. The Li(2)-O(2) bond length is 1.89 Å. The Li(2)-O(4) bond length is 2.11 Å. The Li(2)-O(5) bond length is 1.96 Å. The Li(2)-O(6) bond length is 2.23 Å. In the third Li site, Li(3) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and corners with three equivalent Mn(1)O4 trigonal pyramids. The Li(3)-O(2) bond length is 1.88 Å. The Li(3)-O(3) bond length is 2.11 Å. The Li(3)-O(4) bond length is 2.08 Å. The Li(3)-O(7) bond length is 2.27 Å. Mn(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form distorted MnO4 trigonal pyramids that share  a cornercorner with one Li(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent Li(3)O4 tetrahedra. The Mn(1)-O(1) bond length is 1.90 Å. The Mn(1)-O(3) bond length is 1.93 Å. The Mn(1)-O(4) bond length is 1.95 Å. The Mn(1)-O(7) bond length is 1.96 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, corners with three equivalent Li(3)O4 tetrahedra, and corners with two equivalent Mn(1)O4 trigonal pyramids. The Si(1)-O(2) bond length is 1.59 Å. The Si(1)-O(3) bond length is 1.66 Å. The Si(1)-O(4) bond length is 1.67 Å. The Si(1)-O(6) bond length is 1.67 Å. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with two equivalent Mn(1)O4 trigonal pyramids. The Si(2)-O(1) bond length is 1.66 Å. The Si(2)-O(5) bond length is 1.60 Å. The Si(2)-O(6) bond length is 1.68 Å. The Si(2)-O(7) bond length is 1.66 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(1), one Mn(1), and one Si(2) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(2), one Li(3), and one Si(1) atom. In the third O site, O(3) is bonded to one Li(1), one Li(3), one Mn(1), and one Si(1) atom to form corner-sharing OLi2MnSi tetrahedra. In the fourth O site, O(4) is bonded to one Li(2), one Li(3), one Mn(1), and one Si(1) atom to form corner-sharing OLi2MnSi tetrahedra. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Li(2), and one Si(2) atom. In the sixth O site, O(6) is bonded in a trigonal non-coplanar geometry to one Li(2), one Si(1), and one Si(2) atom. In the seventh O site, O(7) is bonded to one Li(1), one Li(3), one Mn(1), and one Si(2) atom to form distorted corner-sharing OLi2MnSi tetrahedra.