The material structure described by MgTiSiO5 crystallizes in the triclinic P1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), one O(10), one O(2), one O(4), and one O(7) atom to form distorted MgO5 square pyramids that share corners with two equivalent Ti(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and edges with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-61°. In the second Mg site, Mg(2) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), one O(8), and one O(9) atom. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(10), one O(2), one O(4), one O(5), one O(7), and one O(9) atom to form TiO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Mg(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 45-46°. In the second Ti site, Ti(2) is bonded to one O(1), one O(10), one O(3), one O(6), one O(8), and one O(9) atom to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-46°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, and corners with three equivalent Mg(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 45-64°. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, and  a cornercorner with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 41-62°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Mg(1), one Ti(2), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Ti(1), and one Si(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mg(2), one Ti(2), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted tetrahedral geometry to one Mg(1), one Mg(2), one Ti(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Mg(2), one Ti(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Mg(2), one Ti(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ti(1), and one Si(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Mg(2), one Ti(2), and one Si(1) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Mg(2), one Ti(1), and one Ti(2) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ti(1), and one Ti(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgTiSiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.431
_cell_length_b   7.094
_cell_length_c   8.594
_cell_angle_alpha   92.322
_cell_angle_beta   144.893
_cell_angle_gamma   74.773
_symmetry_Int_Tables_number   1
_cell_volume   174.440
_cell_formula_units_Z   2
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  0.446  0.298  0.160  1.0
  Mg  Mg1  1  0.541  0.738  0.846  1.0
  Ti  Ti2  1  0.506  0.501  0.513  1.0
  Ti  Ti3  1  0.495  0.002  0.490  1.0
  Si  Si4  1  0.489  0.231  0.811  1.0
  Si  Si5  1  0.514  0.745  0.189  1.0
  O  O6  1  0.169  0.155  0.526  1.0
  O  O7  1  0.682  0.380  0.811  1.0
  O  O8  1  0.824  0.826  0.468  1.0
  O  O9  1  0.327  0.595  0.194  1.0
  O  O10  1  0.824  0.604  0.199  1.0
  O  O11  1  0.112  0.934  0.894  1.0
  O  O12  1  0.187  0.368  0.808  1.0
  O  O13  1  0.890  0.026  0.092  1.0
  O  O14  1  0.526  0.737  0.602  1.0
  O  O15  1  0.468  0.240  0.399  1.0
[/CIF]
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The material structure described by MgTiSiO5 crystallizes in the triclinic P1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), one O(10), one O(2), one O(4), and one O(7) atom to form distorted MgO5 square pyramids that share corners with two equivalent Ti(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and edges with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-61°. In the second Mg site, Mg(2) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), one O(8), and one O(9) atom. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(10), one O(2), one O(4), one O(5), one O(7), and one O(9) atom to form TiO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Mg(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 45-46°. In the second Ti site, Ti(2) is bonded to one O(1), one O(10), one O(3), one O(6), one O(8), and one O(9) atom to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-46°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, and corners with three equivalent Mg(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 45-64°. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, and  a cornercorner with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 41-62°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Mg(1), one Ti(2), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Ti(1), and one Si(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mg(2), one Ti(2), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted tetrahedral geometry to one Mg(1), one Mg(2), one Ti(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Mg(2), one Ti(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Mg(2), one Ti(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ti(1), and one Si(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Mg(2), one Ti(2), and one Si(1) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Mg(2), one Ti(1), and one Ti(2) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ti(1), and one Ti(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgTiSiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.431
_cell_length_b   7.094
_cell_length_c   8.594
_cell_angle_alpha   92.322
_cell_angle_beta   144.893
_cell_angle_gamma   74.773
_symmetry_Int_Tables_number   1
_cell_volume   174.440
_cell_formula_units_Z   2
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  0.446  0.298  0.160  1.0
  Mg  Mg1  1  0.541  0.738  0.846  1.0
  Ti  Ti2  1  0.506  0.501  0.513  1.0
  Ti  Ti3  1  0.495  0.002  0.490  1.0
  Si  Si4  1  0.489  0.231  0.811  1.0
  Si  Si5  1  0.514  0.745  0.189  1.0
  O  O6  1  0.169  0.155  0.526  1.0
  O  O7  1  0.682  0.380  0.811  1.0
  O  O8  1  0.824  0.826  0.468  1.0
  O  O9  1  0.327  0.595  0.194  1.0
  O  O10  1  0.824  0.604  0.199  1.0
  O  O11  1  0.112  0.934  0.894  1.0
  O  O12  1  0.187  0.368  0.808  1.0
  O  O13  1  0.890  0.026  0.092  1.0
  O  O14  1  0.526  0.737  0.602  1.0
  O  O15  1  0.468  0.240  0.399  1.0
[/CIF]
.