LiMg6BO7 crystallizes in the tetragonal P4mm space group. Li(1) is bonded to one O(1) and four equivalent O(4) atoms to form distorted LiO5 square pyramids that share corners with four equivalent Li(1)O5 square pyramids, edges with four equivalent Mg(1)O6 octahedra, and edges with four equivalent Mg(4)O6 octahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2), one O(3), and four equivalent O(4) 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 Mg(4)O6 octahedra, and edges with four equivalent Li(1)O5 square pyramids. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to one O(2), one O(3), and four equivalent O(5) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the third Mg site, Mg(3) is bonded in a square co-planar geometry to one O(4), one O(5), and two equivalent O(2) atoms. In the fourth Mg site, Mg(4) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with four equivalent Mg(4)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, and edges with two equivalent Li(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 1-27°. B(1) is bonded in a distorted single-bond geometry to one O(1) and four equivalent O(5) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Li(1), four equivalent Mg(4), and one B(1) atom. 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 two equivalent O(3)Mg6 octahedra, corners with four equivalent O(2)Mg6 octahedra, edges with four equivalent O(4)Li2Mg4 octahedra, and edges with four equivalent O(5)Mg4B2 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third O site, O(3) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(4) atoms to form OMg6 octahedra that share corners with two equivalent O(2)Mg6 octahedra, corners with four equivalent O(3)Mg6 octahedra, edges with four equivalent O(4)Li2Mg4 octahedra, and edges with four equivalent O(5)Mg4B2 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the fourth O site, O(4) is bonded to two equivalent Li(1), one Mg(3), one Mg(4), and two equivalent Mg(1) atoms to form OLi2Mg4 octahedra that share corners with two equivalent O(5)Mg4B2 octahedra, corners with four equivalent O(4)Li2Mg4 octahedra, edges with two equivalent O(2)Mg6 octahedra, edges with two equivalent O(3)Mg6 octahedra, and edges with four equivalent O(4)Li2Mg4 octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to one Mg(3), one Mg(4), two equivalent Mg(2), and two equivalent B(1) atoms to form OMg4B2 octahedra that share corners with two equivalent O(4)Li2Mg4 octahedra, corners with four equivalent O(5)Mg4B2 octahedra, edges with two equivalent O(2)Mg6 octahedra, edges with two equivalent O(3)Mg6 octahedra, and edges with four equivalent O(5)Mg4B2 octahedra. The corner-sharing octahedral tilt angles range from 0-4°.
LiMg6BO7 crystallizes in the tetragonal P4mm space group. Li(1) is bonded to one O(1) and four equivalent O(4) atoms to form distorted LiO5 square pyramids that share corners with four equivalent Li(1)O5 square pyramids, edges with four equivalent Mg(1)O6 octahedra, and edges with four equivalent Mg(4)O6 octahedra. The Li(1)-O(1) bond length is 2.56 Å. All Li(1)-O(4) bond lengths are 2.14 Å. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2), one O(3), and four equivalent O(4) 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 Mg(4)O6 octahedra, and edges with four equivalent Li(1)O5 square pyramids. The corner-sharing octahedra are not tilted. The Mg(1)-O(2) bond length is 2.04 Å. The Mg(1)-O(3) bond length is 2.04 Å. All Mg(1)-O(4) bond lengths are 2.14 Å. In the second Mg site, Mg(2) is bonded to one O(2), one O(3), and four equivalent O(5) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. The Mg(2)-O(2) bond length is 2.02 Å. The Mg(2)-O(3) bond length is 2.03 Å. All Mg(2)-O(5) bond lengths are 2.14 Å. In the third Mg site, Mg(3) is bonded in a square co-planar geometry to one O(4), one O(5), and two equivalent O(2) atoms. The Mg(3)-O(4) bond length is 2.07 Å. The Mg(3)-O(5) bond length is 1.98 Å. Both Mg(3)-O(2) bond lengths are 2.14 Å. In the fourth Mg site, Mg(4) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with four equivalent Mg(4)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, and edges with two equivalent Li(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 1-27°. The Mg(4)-O(4) bond length is 2.06 Å. The Mg(4)-O(5) bond length is 2.02 Å. Both Mg(4)-O(1) bond lengths are 2.20 Å. Both Mg(4)-O(3) bond lengths are 2.14 Å. B(1) is bonded in a distorted single-bond geometry to one O(1) and four equivalent O(5) atoms. The B(1)-O(1) bond length is 1.44 Å. All B(1)-O(5) bond lengths are 2.14 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Li(1), four equivalent Mg(4), and one B(1) atom. 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 two equivalent O(3)Mg6 octahedra, corners with four equivalent O(2)Mg6 octahedra, edges with four equivalent O(4)Li2Mg4 octahedra, and edges with four equivalent O(5)Mg4B2 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third O site, O(3) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(4) atoms to form OMg6 octahedra that share corners with two equivalent O(2)Mg6 octahedra, corners with four equivalent O(3)Mg6 octahedra, edges with four equivalent O(4)Li2Mg4 octahedra, and edges with four equivalent O(5)Mg4B2 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the fourth O site, O(4) is bonded to two equivalent Li(1), one Mg(3), one Mg(4), and two equivalent Mg(1) atoms to form OLi2Mg4 octahedra that share corners with two equivalent O(5)Mg4B2 octahedra, corners with four equivalent O(4)Li2Mg4 octahedra, edges with two equivalent O(2)Mg6 octahedra, edges with two equivalent O(3)Mg6 octahedra, and edges with four equivalent O(4)Li2Mg4 octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to one Mg(3), one Mg(4), two equivalent Mg(2), and two equivalent B(1) atoms to form OMg4B2 octahedra that share corners with two equivalent O(4)Li2Mg4 octahedra, corners with four equivalent O(5)Mg4B2 octahedra, edges with two equivalent O(2)Mg6 octahedra, edges with two equivalent O(3)Mg6 octahedra, and edges with four equivalent O(5)Mg4B2 octahedra. The corner-sharing octahedral tilt angles range from 0-4°.