Mg6TiBO8 crystallizes in the tetragonal P4/mmm space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)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 Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Ti(1)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. Ti(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form TiO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Ti(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. B(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), four equivalent Mg(3), and one Ti(1) atom to form OMg5Ti octahedra that share corners with six equivalent O(1)Mg5Ti octahedra, edges with four equivalent O(3)Mg2Ti2B2 octahedra, edges with four equivalent O(4)Mg6 octahedra, and edges with four equivalent O(2)Mg5 square pyramids. The corner-sharing octahedral tilt angles range from 0-3°. In the second O site, O(2) is bonded to one Mg(2) and four equivalent Mg(3) atoms to form OMg5 square pyramids that share corners with four equivalent O(3)Mg2Ti2B2 octahedra, corners with five equivalent O(2)Mg5 square pyramids, edges with four equivalent O(1)Mg5Ti octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles are 87°. In the third O site, O(3) is bonded to two equivalent Mg(3), two equivalent Ti(1), and two equivalent B(1) atoms to form OMg2Ti2B2 octahedra that share corners with two equivalent O(4)Mg6 octahedra, corners with four equivalent O(3)Mg2Ti2B2 octahedra, corners with four equivalent O(2)Mg5 square pyramids, edges with four equivalent O(3)Mg2Ti2B2 octahedra, and edges with four equivalent O(1)Mg5Ti octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(3)Mg2Ti2B2 octahedra, corners with four equivalent O(4)Mg6 octahedra, edges with four equivalent O(1)Mg5Ti octahedra, edges with four equivalent O(4)Mg6 octahedra, and edges with four equivalent O(2)Mg5 square pyramids. The corner-sharing octahedra are not tilted.
Mg6TiBO8 crystallizes in the tetragonal P4/mmm space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. Both Mg(1)-O(1) bond lengths are 2.23 Å. All Mg(1)-O(4) 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 2.06 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 Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Ti(1)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. The Mg(3)-O(3) bond length is 2.19 Å. The Mg(3)-O(4) bond length is 2.18 Å. Both Mg(3)-O(1) bond lengths are 2.12 Å. Both Mg(3)-O(2) bond lengths are 2.12 Å. Ti(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form TiO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Ti(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. Both Ti(1)-O(1) bond lengths are 2.14 Å. All Ti(1)-O(3) bond lengths are 2.11 Å. B(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. All B(1)-O(3) bond lengths are 2.11 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), four equivalent Mg(3), and one Ti(1) atom to form OMg5Ti octahedra that share corners with six equivalent O(1)Mg5Ti octahedra, edges with four equivalent O(3)Mg2Ti2B2 octahedra, edges with four equivalent O(4)Mg6 octahedra, and edges with four equivalent O(2)Mg5 square pyramids. The corner-sharing octahedral tilt angles range from 0-3°. In the second O site, O(2) is bonded to one Mg(2) and four equivalent Mg(3) atoms to form OMg5 square pyramids that share corners with four equivalent O(3)Mg2Ti2B2 octahedra, corners with five equivalent O(2)Mg5 square pyramids, edges with four equivalent O(1)Mg5Ti octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles are 87°. In the third O site, O(3) is bonded to two equivalent Mg(3), two equivalent Ti(1), and two equivalent B(1) atoms to form OMg2Ti2B2 octahedra that share corners with two equivalent O(4)Mg6 octahedra, corners with four equivalent O(3)Mg2Ti2B2 octahedra, corners with four equivalent O(2)Mg5 square pyramids, edges with four equivalent O(3)Mg2Ti2B2 octahedra, and edges with four equivalent O(1)Mg5Ti octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(3)Mg2Ti2B2 octahedra, corners with four equivalent O(4)Mg6 octahedra, edges with four equivalent O(1)Mg5Ti octahedra, edges with four equivalent O(4)Mg6 octahedra, and edges with four equivalent O(2)Mg5 square pyramids. The corner-sharing octahedra are not tilted.