LiMg6CO8 crystallizes in the tetragonal P4/mmm space group. Li(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form LiO6 octahedra that share corners with four equivalent Li(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(3)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-20°. C(1) is bonded in a distorted linear geometry to two equivalent O(1) and four equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), four equivalent Mg(3), and one C(1) atom to form distorted OLiMg4C octahedra that share corners with six equivalent O(1)LiMg4C octahedra, edges with four equivalent O(3)Li2Mg4 octahedra, edges with four equivalent O(4)Mg4C2 octahedra, and edges with four equivalent O(2)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-20°. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(3) atoms to form OMg6 octahedra that share corners with six equivalent O(2)Mg6 octahedra, edges with four equivalent O(3)Li2Mg4 octahedra, edges with four equivalent O(1)LiMg4C octahedra, and edges with four equivalent O(4)Mg4C2 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third O site, O(3) is bonded to two equivalent Li(1), two equivalent Mg(1), and two equivalent Mg(3) atoms to form OLi2Mg4 octahedra that share corners with two equivalent O(4)Mg4C2 octahedra, corners with four equivalent O(3)Li2Mg4 octahedra, edges with four equivalent O(3)Li2Mg4 octahedra, edges with four equivalent O(1)LiMg4C octahedra, and edges with four equivalent O(2)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Mg(2), two equivalent Mg(3), and two equivalent C(1) atoms to form distorted OMg4C2 octahedra that share corners with two equivalent O(3)Li2Mg4 octahedra, corners with four equivalent O(4)Mg4C2 octahedra, edges with four equivalent O(1)LiMg4C octahedra, edges with four equivalent O(4)Mg4C2 octahedra, and edges with four equivalent O(2)Mg6 octahedra. The corner-sharing octahedra are not tilted.
LiMg6CO8 crystallizes in the tetragonal P4/mmm space group. Li(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form LiO6 octahedra that share corners with four equivalent Li(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. Both Li(1)-O(1) bond lengths are 2.43 Å. All Li(1)-O(3) bond lengths are 2.11 Å. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. Both Mg(1)-O(2) bond lengths are 2.09 Å. All Mg(1)-O(3) bond lengths are 2.11 Å. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. Both Mg(2)-O(2) bond lengths are 2.05 Å. All Mg(2)-O(4) bond lengths are 2.11 Å. In the third Mg site, Mg(3) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(3)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-20°. The Mg(3)-O(3) bond length is 2.05 Å. The Mg(3)-O(4) bond length is 2.09 Å. Both Mg(3)-O(1) bond lengths are 2.14 Å. Both Mg(3)-O(2) bond lengths are 2.11 Å. C(1) is bonded in a distorted linear geometry to two equivalent O(1) and four equivalent O(4) atoms. Both C(1)-O(1) bond lengths are 1.71 Å. All C(1)-O(4) bond lengths are 2.11 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), four equivalent Mg(3), and one C(1) atom to form distorted OLiMg4C octahedra that share corners with six equivalent O(1)LiMg4C octahedra, edges with four equivalent O(3)Li2Mg4 octahedra, edges with four equivalent O(4)Mg4C2 octahedra, and edges with four equivalent O(2)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-20°. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(3) atoms to form OMg6 octahedra that share corners with six equivalent O(2)Mg6 octahedra, edges with four equivalent O(3)Li2Mg4 octahedra, edges with four equivalent O(1)LiMg4C octahedra, and edges with four equivalent O(4)Mg4C2 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third O site, O(3) is bonded to two equivalent Li(1), two equivalent Mg(1), and two equivalent Mg(3) atoms to form OLi2Mg4 octahedra that share corners with two equivalent O(4)Mg4C2 octahedra, corners with four equivalent O(3)Li2Mg4 octahedra, edges with four equivalent O(3)Li2Mg4 octahedra, edges with four equivalent O(1)LiMg4C octahedra, and edges with four equivalent O(2)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Mg(2), two equivalent Mg(3), and two equivalent C(1) atoms to form distorted OMg4C2 octahedra that share corners with two equivalent O(3)Li2Mg4 octahedra, corners with four equivalent O(4)Mg4C2 octahedra, edges with four equivalent O(1)LiMg4C octahedra, edges with four equivalent O(4)Mg4C2 octahedra, and edges with four equivalent O(2)Mg6 octahedra. The corner-sharing octahedra are not tilted.