The structure described by MgTi4O8 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(2), one O(5), one O(6), and two equivalent O(3) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent Mg(1)O5 trigonal bipyramids,  an edgeedge with one Ti(4)O6 octahedra, edges with two equivalent Ti(2)O6 octahedra, and edges with two equivalent Ti(3)O6 octahedra. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), one O(6), and two equivalent O(7) atoms. In the second Ti site, Ti(2) is bonded to one O(1), one O(3), one O(4), one O(7), and two equivalent O(2) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra,  an edgeedge with one Ti(4)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 4-24°. In the third Ti site, Ti(3) is bonded to one O(1), one O(3), one O(7), one O(8), and two equivalent O(5) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(4)O6 octahedra, corners with two equivalent Ti(3)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, edges with two equivalent Ti(4)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 4-18°. In the fourth Ti site, Ti(4) is bonded to one O(1), one O(4), one O(5), one O(6), and two equivalent O(8) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Ti(4)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, edges with two equivalent Ti(3)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 12-28°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Ti(2), one Ti(3), and one Ti(4) atom. In the second O site, O(2) is bonded to one Mg(1), one Ti(1), and two equivalent Ti(2) atoms to form OMgTi3 trigonal pyramids that share corners with two equivalent O(5)MgTi4 square pyramids, corners with two equivalent O(2)MgTi3 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1), one Ti(2), and one Ti(3) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ti(1), one Ti(2), and one Ti(4) atom. In the fifth O site, O(5) is bonded to one Mg(1), one Ti(1), one Ti(4), and two equivalent Ti(3) atoms to form distorted OMgTi4 square pyramids that share corners with two equivalent O(5)MgTi4 square pyramids, corners with two equivalent O(2)MgTi3 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the sixth O site, O(6) is bonded in a T-shaped geometry to one Mg(1), one Ti(1), and one Ti(4) atom. In the seventh O site, O(7) is bonded to one Ti(2), one Ti(3), and two equivalent Ti(1) atoms to form OTi4 trigonal pyramids that share corners with two equivalent O(7)Ti4 trigonal pyramids, edges with two equivalent O(5)MgTi4 square pyramids, and edges with two equivalent O(2)MgTi3 trigonal pyramids. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Ti(3) and two equivalent Ti(4) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgTi4O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.881
_cell_length_b   6.635
_cell_length_c   6.639
_cell_angle_alpha   106.577
_cell_angle_beta   89.996
_cell_angle_gamma   107.010
_symmetry_Int_Tables_number   1
_cell_volume   156.017
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Mg  Mg0  1  0.319  0.637  0.994  1.0
  Ti  Ti1  1  0.192  0.383  0.290  1.0
  Ti  Ti2  1  0.903  0.805  0.325  1.0
  Ti  Ti3  1  0.791  0.583  0.672  1.0
  Ti  Ti4  1  0.094  0.188  0.688  1.0
  O  O5  1  0.940  0.880  0.649  1.0
  O  O6  1  0.368  0.736  0.309  1.0
  O  O7  1  0.853  0.705  0.997  1.0
  O  O8  1  0.057  0.113  0.354  1.0
  O  O9  1  0.268  0.535  0.672  1.0
  O  O10  1  0.155  0.310  0.003  1.0
  O  O11  1  0.734  0.468  0.344  1.0
  O  O12  1  0.631  0.261  0.683  1.0
[/CIF]
.
The structure described by MgTi4O8 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(2), one O(5), one O(6), and two equivalent O(3) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent Mg(1)O5 trigonal bipyramids,  an edgeedge with one Ti(4)O6 octahedra, edges with two equivalent Ti(2)O6 octahedra, and edges with two equivalent Ti(3)O6 octahedra. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), one O(6), and two equivalent O(7) atoms. In the second Ti site, Ti(2) is bonded to one O(1), one O(3), one O(4), one O(7), and two equivalent O(2) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra,  an edgeedge with one Ti(4)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 4-24°. In the third Ti site, Ti(3) is bonded to one O(1), one O(3), one O(7), one O(8), and two equivalent O(5) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(4)O6 octahedra, corners with two equivalent Ti(3)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, edges with two equivalent Ti(4)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 4-18°. In the fourth Ti site, Ti(4) is bonded to one O(1), one O(4), one O(5), one O(6), and two equivalent O(8) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Ti(4)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, edges with two equivalent Ti(3)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 12-28°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Ti(2), one Ti(3), and one Ti(4) atom. In the second O site, O(2) is bonded to one Mg(1), one Ti(1), and two equivalent Ti(2) atoms to form OMgTi3 trigonal pyramids that share corners with two equivalent O(5)MgTi4 square pyramids, corners with two equivalent O(2)MgTi3 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1), one Ti(2), and one Ti(3) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ti(1), one Ti(2), and one Ti(4) atom. In the fifth O site, O(5) is bonded to one Mg(1), one Ti(1), one Ti(4), and two equivalent Ti(3) atoms to form distorted OMgTi4 square pyramids that share corners with two equivalent O(5)MgTi4 square pyramids, corners with two equivalent O(2)MgTi3 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the sixth O site, O(6) is bonded in a T-shaped geometry to one Mg(1), one Ti(1), and one Ti(4) atom. In the seventh O site, O(7) is bonded to one Ti(2), one Ti(3), and two equivalent Ti(1) atoms to form OTi4 trigonal pyramids that share corners with two equivalent O(7)Ti4 trigonal pyramids, edges with two equivalent O(5)MgTi4 square pyramids, and edges with two equivalent O(2)MgTi3 trigonal pyramids. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Ti(3) and two equivalent Ti(4) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgTi4O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.881
_cell_length_b   6.635
_cell_length_c   6.639
_cell_angle_alpha   106.577
_cell_angle_beta   89.996
_cell_angle_gamma   107.010
_symmetry_Int_Tables_number   1
_cell_volume   156.017
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Mg  Mg0  1  0.319  0.637  0.994  1.0
  Ti  Ti1  1  0.192  0.383  0.290  1.0
  Ti  Ti2  1  0.903  0.805  0.325  1.0
  Ti  Ti3  1  0.791  0.583  0.672  1.0
  Ti  Ti4  1  0.094  0.188  0.688  1.0
  O  O5  1  0.940  0.880  0.649  1.0
  O  O6  1  0.368  0.736  0.309  1.0
  O  O7  1  0.853  0.705  0.997  1.0
  O  O8  1  0.057  0.113  0.354  1.0
  O  O9  1  0.268  0.535  0.672  1.0
  O  O10  1  0.155  0.310  0.003  1.0
  O  O11  1  0.734  0.468  0.344  1.0
  O  O12  1  0.631  0.261  0.683  1.0
[/CIF]
.