Li2Mn2Si4O11 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a see-saw-like geometry to one O(1), one O(2), one O(3), 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(3), one O(4), one O(6), and one O(9) atom. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(7), one O(8), one O(9), and two equivalent O(11) atoms to form MnO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one Mn(1)O6 octahedra, and edges with three equivalent Mn(2)O6 octahedra. In the second Mn site, Mn(2) is bonded to one O(11), one O(3), one O(7), one O(9), and two equivalent O(8) atoms to form MnO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one Mn(2)O6 octahedra, and edges with three equivalent Mn(1)O6 octahedra. There are four 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(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 6-60°. In the second Si site, Si(2) is bonded to one O(10), one O(11), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-65°. In the third Si site, Si(3) is bonded to one O(2), one O(5), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-63°. In the fourth Si site, Si(4) is bonded to one O(10), one O(6), one O(7), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-65°. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a see-saw-like geometry to one Li(1), one Li(2), one Mn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Si(1), and one Si(3) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Mn(2), and one Si(1) atom to form distorted OLi2MnSi trigonal pyramids that share  a cornercorner with one O(11)Mn3Si tetrahedra and  an edgeedge with one O(9)LiMn2Si trigonal pyramid. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(2), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one Si(3), and one Si(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Li(1), one Mn(1), one Mn(2), and one Si(4) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Mn(1), two equivalent Mn(2), and one Si(3) atom. In the ninth O site, O(9) is bonded to one Li(2), one Mn(1), one Mn(2), and one Si(4) atom to form OLiMn2Si trigonal pyramids that share  a cornercorner with one O(11)Mn3Si tetrahedra,  an edgeedge with one O(11)Mn3Si tetrahedra, and  an edgeedge with one O(3)Li2MnSi trigonal pyramid. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) is bonded to one Mn(2), two equivalent Mn(1), and one Si(2) atom to form distorted OMn3Si tetrahedra that share  a cornercorner with one O(3)Li2MnSi trigonal pyramid,  a cornercorner with one O(9)LiMn2Si trigonal pyramid,  an edgeedge with one O(11)Mn3Si tetrahedra, and  an edgeedge with one O(9)LiMn2Si trigonal pyramid.
Li2Mn2Si4O11 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a see-saw-like geometry to one O(1), one O(2), one O(3), and one O(7) atom. The Li(1)-O(1) bond length is 2.11 Å. The Li(1)-O(2) bond length is 2.26 Å. The Li(1)-O(3) bond length is 2.11 Å. The Li(1)-O(7) bond length is 2.11 Å. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(6), and one O(9) atom. The Li(2)-O(1) bond length is 2.21 Å. The Li(2)-O(3) bond length is 1.97 Å. The Li(2)-O(4) bond length is 2.06 Å. The Li(2)-O(6) bond length is 2.47 Å. The Li(2)-O(9) bond length is 2.19 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(7), one O(8), one O(9), and two equivalent O(11) atoms to form MnO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one Mn(1)O6 octahedra, and edges with three equivalent Mn(2)O6 octahedra. The Mn(1)-O(1) bond length is 2.10 Å. The Mn(1)-O(7) bond length is 2.30 Å. The Mn(1)-O(8) bond length is 2.29 Å. The Mn(1)-O(9) bond length is 2.21 Å. There is one shorter (2.22 Å) and one longer (2.27 Å) Mn(1)-O(11) bond length. In the second Mn site, Mn(2) is bonded to one O(11), one O(3), one O(7), one O(9), and two equivalent O(8) atoms to form MnO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one Mn(2)O6 octahedra, and edges with three equivalent Mn(1)O6 octahedra. The Mn(2)-O(11) bond length is 2.31 Å. The Mn(2)-O(3) bond length is 2.14 Å. The Mn(2)-O(7) bond length is 2.23 Å. The Mn(2)-O(9) bond length is 2.21 Å. There is one shorter (2.14 Å) and one longer (2.46 Å) Mn(2)-O(8) bond length. There are four 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(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 6-60°. The Si(1)-O(1) bond length is 1.60 Å. The Si(1)-O(2) bond length is 1.67 Å. The Si(1)-O(3) bond length is 1.62 Å. The Si(1)-O(4) bond length is 1.69 Å. In the second Si site, Si(2) is bonded to one O(10), one O(11), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-65°. The Si(2)-O(10) bond length is 1.64 Å. The Si(2)-O(11) bond length is 1.62 Å. The Si(2)-O(4) bond length is 1.65 Å. The Si(2)-O(5) bond length is 1.64 Å. In the third Si site, Si(3) is bonded to one O(2), one O(5), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-63°. The Si(3)-O(2) bond length is 1.64 Å. The Si(3)-O(5) bond length is 1.63 Å. The Si(3)-O(6) bond length is 1.65 Å. The Si(3)-O(8) bond length is 1.62 Å. In the fourth Si site, Si(4) is bonded to one O(10), one O(6), one O(7), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-65°. The Si(4)-O(10) bond length is 1.67 Å. The Si(4)-O(6) bond length is 1.68 Å. The Si(4)-O(7) bond length is 1.63 Å. The Si(4)-O(9) bond length is 1.62 Å. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a see-saw-like geometry to one Li(1), one Li(2), one Mn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Si(1), and one Si(3) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Mn(2), and one Si(1) atom to form distorted OLi2MnSi trigonal pyramids that share  a cornercorner with one O(11)Mn3Si tetrahedra and  an edgeedge with one O(9)LiMn2Si trigonal pyramid. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(2), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one Si(3), and one Si(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Li(1), one Mn(1), one Mn(2), and one Si(4) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Mn(1), two equivalent Mn(2), and one Si(3) atom. In the ninth O site, O(9) is bonded to one Li(2), one Mn(1), one Mn(2), and one Si(4) atom to form OLiMn2Si trigonal pyramids that share  a cornercorner with one O(11)Mn3Si tetrahedra,  an edgeedge with one O(11)Mn3Si tetrahedra, and  an edgeedge with one O(3)Li2MnSi trigonal pyramid. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) is bonded to one Mn(2), two equivalent Mn(1), and one Si(2) atom to form distorted OMn3Si tetrahedra that share  a cornercorner with one O(3)Li2MnSi trigonal pyramid,  a cornercorner with one O(9)LiMn2Si trigonal pyramid,  an edgeedge with one O(11)Mn3Si tetrahedra, and  an edgeedge with one O(9)LiMn2Si trigonal pyramid.