The structure described by MgTi4O8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form distorted MgO6 octahedra that share  a cornercorner with one Ti(1)O5 trigonal bipyramid,  a cornercorner with one Ti(2)O5 trigonal bipyramid,  a cornercorner with one Ti(3)O5 trigonal bipyramid,  a cornercorner with one Ti(4)O5 trigonal bipyramid, edges with two equivalent Mg(1)O6 octahedra,  an edgeedge with one Ti(1)O5 trigonal bipyramid,  an edgeedge with one Ti(2)O5 trigonal bipyramid,  an edgeedge with one Ti(3)O5 trigonal bipyramid, and  an edgeedge with one Ti(4)O5 trigonal bipyramid. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(4), one O(7), and two equivalent O(5) atoms to form TiO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(2)O5 trigonal bipyramid,  a cornercorner with one Ti(3)O5 trigonal bipyramid, corners with two equivalent Ti(1)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Ti(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 69°. In the second Ti site, Ti(2) is bonded to one O(3), one O(4), one O(8), and two equivalent O(6) atoms to form TiO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(1)O5 trigonal bipyramid,  a cornercorner with one Ti(4)O5 trigonal bipyramid, corners with two equivalent Ti(2)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Ti(3)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 80°. In the third Ti site, Ti(3) is bonded to one O(1), one O(2), one O(6), and two equivalent O(8) atoms to form TiO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(1)O5 trigonal bipyramid,  a cornercorner with one Ti(4)O5 trigonal bipyramid, corners with two equivalent Ti(3)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Ti(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 80°. In the fourth Ti site, Ti(4) is bonded to one O(1), one O(3), one O(5), and two equivalent O(7) atoms to form TiO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(2)O5 trigonal bipyramid,  a cornercorner with one Ti(3)O5 trigonal bipyramid, corners with two equivalent Ti(4)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Ti(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 70°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Ti(3), and one Ti(4) atom to form a mixture of corner and edge-sharing OMg2Ti2 trigonal pyramids. In the second O site, O(2) is bonded in a T-shaped geometry to one Mg(1), one Ti(1), and one Ti(3) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Mg(1), one Ti(2), and one Ti(4) atom. In the fourth O site, O(4) is bonded to two equivalent Mg(1), one Ti(1), and one Ti(2) atom to form a mixture of corner and edge-sharing OMg2Ti2 trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Ti(4) and two equivalent Ti(1) atoms. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Ti(3) and two equivalent Ti(2) atoms. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Ti(1) and two equivalent Ti(4) atoms. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Ti(2) and two equivalent Ti(3) atoms. is represented by the CIF file [CIF]
data_MgTi4O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.260
_cell_length_b   7.661
_cell_length_c   7.850
_cell_angle_alpha   82.861
_cell_angle_beta   77.992
_cell_angle_gamma   77.550
_symmetry_Int_Tables_number   1
_cell_volume   186.633
_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  0.355  0.501  0.500  1.0
  Ti  Ti1  1  0.860  0.147  0.567  1.0
  Ti  Ti2  1  0.972  0.476  0.162  1.0
  Ti  Ti3  1  0.613  0.523  0.837  1.0
  Ti  Ti4  1  0.575  0.854  0.431  1.0
  O  O5  1  0.736  0.654  0.600  1.0
  O  O6  1  0.525  0.337  0.718  1.0
  O  O7  1  0.583  0.662  0.282  1.0
  O  O8  1  0.996  0.346  0.401  1.0
  O  O9  1  0.377  0.027  0.632  1.0
  O  O10  1  0.583  0.376  0.081  1.0
  O  O11  1  0.035  0.974  0.367  1.0
  O  O12  1  0.040  0.622  0.921  1.0
[/CIF]
.
The structure described by MgTi4O8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form distorted MgO6 octahedra that share  a cornercorner with one Ti(1)O5 trigonal bipyramid,  a cornercorner with one Ti(2)O5 trigonal bipyramid,  a cornercorner with one Ti(3)O5 trigonal bipyramid,  a cornercorner with one Ti(4)O5 trigonal bipyramid, edges with two equivalent Mg(1)O6 octahedra,  an edgeedge with one Ti(1)O5 trigonal bipyramid,  an edgeedge with one Ti(2)O5 trigonal bipyramid,  an edgeedge with one Ti(3)O5 trigonal bipyramid, and  an edgeedge with one Ti(4)O5 trigonal bipyramid. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(4), one O(7), and two equivalent O(5) atoms to form TiO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(2)O5 trigonal bipyramid,  a cornercorner with one Ti(3)O5 trigonal bipyramid, corners with two equivalent Ti(1)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Ti(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 69°. In the second Ti site, Ti(2) is bonded to one O(3), one O(4), one O(8), and two equivalent O(6) atoms to form TiO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(1)O5 trigonal bipyramid,  a cornercorner with one Ti(4)O5 trigonal bipyramid, corners with two equivalent Ti(2)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Ti(3)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 80°. In the third Ti site, Ti(3) is bonded to one O(1), one O(2), one O(6), and two equivalent O(8) atoms to form TiO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(1)O5 trigonal bipyramid,  a cornercorner with one Ti(4)O5 trigonal bipyramid, corners with two equivalent Ti(3)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Ti(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 80°. In the fourth Ti site, Ti(4) is bonded to one O(1), one O(3), one O(5), and two equivalent O(7) atoms to form TiO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(2)O5 trigonal bipyramid,  a cornercorner with one Ti(3)O5 trigonal bipyramid, corners with two equivalent Ti(4)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Ti(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 70°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Ti(3), and one Ti(4) atom to form a mixture of corner and edge-sharing OMg2Ti2 trigonal pyramids. In the second O site, O(2) is bonded in a T-shaped geometry to one Mg(1), one Ti(1), and one Ti(3) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Mg(1), one Ti(2), and one Ti(4) atom. In the fourth O site, O(4) is bonded to two equivalent Mg(1), one Ti(1), and one Ti(2) atom to form a mixture of corner and edge-sharing OMg2Ti2 trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Ti(4) and two equivalent Ti(1) atoms. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Ti(3) and two equivalent Ti(2) atoms. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Ti(1) and two equivalent Ti(4) atoms. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Ti(2) and two equivalent Ti(3) atoms. is represented by the CIF file [CIF]
data_MgTi4O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.260
_cell_length_b   7.661
_cell_length_c   7.850
_cell_angle_alpha   82.861
_cell_angle_beta   77.992
_cell_angle_gamma   77.550
_symmetry_Int_Tables_number   1
_cell_volume   186.633
_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  0.355  0.501  0.500  1.0
  Ti  Ti1  1  0.860  0.147  0.567  1.0
  Ti  Ti2  1  0.972  0.476  0.162  1.0
  Ti  Ti3  1  0.613  0.523  0.837  1.0
  Ti  Ti4  1  0.575  0.854  0.431  1.0
  O  O5  1  0.736  0.654  0.600  1.0
  O  O6  1  0.525  0.337  0.718  1.0
  O  O7  1  0.583  0.662  0.282  1.0
  O  O8  1  0.996  0.346  0.401  1.0
  O  O9  1  0.377  0.027  0.632  1.0
  O  O10  1  0.583  0.376  0.081  1.0
  O  O11  1  0.035  0.974  0.367  1.0
  O  O12  1  0.040  0.622  0.921  1.0
[/CIF]
.