The compound described by Mg2Ti7O15 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form distorted MgO6 octahedra that share  a cornercorner with one Mg(2)O6 octahedra, corners with two equivalent Ti(3)O6 octahedra, edges with two equivalent Ti(3)O6 octahedra, and edges with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-46°. In the second Mg site, Mg(2) is bonded to one O(3), one O(9), two equivalent O(6), and two equivalent O(8) atoms to form distorted MgO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, edges with two equivalent Ti(3)O6 octahedra, and edges with four equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-46°. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(4), one O(5), one O(7), and two equivalent O(2) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(3)O6 octahedra,  an edgeedge with one Ti(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-48°. In the second Ti site, Ti(2) is bonded to one O(5), one O(9), two equivalent O(6), and two equivalent O(8) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(3)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-51°. In the third Ti site, Ti(3) is bonded to one O(1), one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form distorted TiO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-49°. In the fourth Ti site, Ti(4) is bonded in a 6-coordinate geometry to one O(4), one O(9), two equivalent O(5), and two equivalent O(7) atoms. There are nine inequivalent O sites. In the first O site, O(7) is bonded in a distorted T-shaped geometry to one Ti(1), one Ti(3), and one Ti(4) atom. In the second O site, O(8) is bonded to one Mg(2), one Ti(3), and two equivalent Ti(2) atoms to form OMgTi3 trigonal pyramids that share  a cornercorner with one O(2)MgTi3 trigonal pyramid,  a cornercorner with one O(8)MgTi3 trigonal pyramid,  a cornercorner with one O(9)MgTi3 trigonal pyramid,  a cornercorner with one O(5)Ti4 trigonal pyramid,  an edgeedge with one O(3)Mg2Ti2 trigonal pyramid,  an edgeedge with one O(8)MgTi3 trigonal pyramid,  an edgeedge with one O(9)MgTi3 trigonal pyramid, and  an edgeedge with one O(5)Ti4 trigonal pyramid. In the third O site, O(9) is bonded to one Mg(2), one Ti(4), and two equivalent Ti(2) atoms to form distorted OMgTi3 trigonal pyramids that share  a cornercorner with one O(3)Mg2Ti2 trigonal pyramid,  a cornercorner with one O(4)MgTi3 trigonal pyramid, corners with two equivalent O(8)MgTi3 trigonal pyramids, edges with two equivalent O(8)MgTi3 trigonal pyramids, and edges with two equivalent O(5)Ti4 trigonal pyramids. In the fourth O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Ti(1), and one Ti(3) atom. In the fifth O site, O(2) is bonded to one Mg(1), one Ti(3), and two equivalent Ti(1) atoms to form OMgTi3 trigonal pyramids that share  a cornercorner with one O(2)MgTi3 trigonal pyramid,  a cornercorner with one O(4)MgTi3 trigonal pyramid,  a cornercorner with one O(8)MgTi3 trigonal pyramid,  a cornercorner with one O(5)Ti4 trigonal pyramid,  an edgeedge with one O(3)Mg2Ti2 trigonal pyramid,  an edgeedge with one O(2)MgTi3 trigonal pyramid,  an edgeedge with one O(4)MgTi3 trigonal pyramid, and  an edgeedge with one O(5)Ti4 trigonal pyramid. In the sixth O site, O(3) is bonded to one Mg(1), one Mg(2), and two equivalent Ti(3) atoms to form distorted OMg2Ti2 trigonal pyramids that share  a cornercorner with one O(4)MgTi3 trigonal pyramid,  a cornercorner with one O(9)MgTi3 trigonal pyramid, corners with two equivalent O(5)Ti4 trigonal pyramids, edges with two equivalent O(2)MgTi3 trigonal pyramids, and edges with two equivalent O(8)MgTi3 trigonal pyramids. In the seventh O site, O(4) is bonded to one Mg(1), one Ti(4), and two equivalent Ti(1) atoms to form distorted OMgTi3 trigonal pyramids that share  a cornercorner with one O(3)Mg2Ti2 trigonal pyramid,  a cornercorner with one O(9)MgTi3 trigonal pyramid, corners with two equivalent O(2)MgTi3 trigonal pyramids, edges with two equivalent O(2)MgTi3 trigonal pyramids, and edges with two equivalent O(5)Ti4 trigonal pyramids. In the eighth O site, O(5) is bonded to one Ti(1), one Ti(2), one Ti(3), and one Ti(4) atom to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(3)Mg2Ti2 trigonal pyramid,  a cornercorner with one O(2)MgTi3 trigonal pyramid,  a cornercorner with one O(8)MgTi3 trigonal pyramid,  a cornercorner with one O(5)Ti4 trigonal pyramid,  an edgeedge with one O(2)MgTi3 trigonal pyramid,  an edgeedge with one O(4)MgTi3 trigonal pyramid,  an edgeedge with one O(8)MgTi3 trigonal pyramid, and  an edgeedge with one O(9)MgTi3 trigonal pyramid. In the ninth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(2) and two equivalent Ti(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2Ti7O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.001
_cell_length_b   5.216
_cell_length_c   10.620
_cell_angle_alpha   83.861
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   550.818
_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  0.750  0.491  0.898  1.0
  Mg  Mg1  1  0.250  0.509  0.102  1.0
  Mg  Mg2  1  0.250  0.175  0.435  1.0
  Mg  Mg3  1  0.750  0.825  0.565  1.0
  Ti  Ti4  1  0.062  0.393  0.880  1.0
  Ti  Ti5  1  0.438  0.393  0.880  1.0
  Ti  Ti6  1  0.562  0.607  0.120  1.0
  Ti  Ti7  1  0.938  0.607  0.120  1.0
  Ti  Ti8  1  0.563  0.275  0.457  1.0
  Ti  Ti9  1  0.937  0.275  0.457  1.0
  Ti  Ti10  1  0.069  0.060  0.213  1.0
  Ti  Ti11  1  0.431  0.060  0.213  1.0
  Ti  Ti12  1  0.063  0.725  0.543  1.0
  Ti  Ti13  1  0.437  0.725  0.543  1.0
  Ti  Ti14  1  0.750  0.158  0.231  1.0
  Ti  Ti15  1  0.250  0.842  0.769  1.0
  Ti  Ti16  1  0.931  0.940  0.787  1.0
  Ti  Ti17  1  0.569  0.940  0.787  1.0
  O  O18  1  0.888  0.242  0.848  1.0
  O  O19  1  0.612  0.242  0.848  1.0
  O  O20  1  0.435  0.314  0.063  1.0
  O  O21  1  0.065  0.314  0.063  1.0
  O  O22  1  0.250  0.204  0.241  1.0
  O  O23  1  0.250  0.541  0.904  1.0
  O  O24  1  0.750  0.459  0.096  1.0
  O  O25  1  0.935  0.686  0.937  1.0
  O  O26  1  0.567  0.350  0.271  1.0
  O  O27  1  0.933  0.350  0.271  1.0
  O  O28  1  0.565  0.686  0.937  1.0
  O  O29  1  0.388  0.758  0.152  1.0
  O  O30  1  0.386  0.424  0.484  1.0
  O  O31  1  0.112  0.758  0.152  1.0
  O  O32  1  0.114  0.424  0.484  1.0
  O  O33  1  0.882  0.914  0.183  1.0
  O  O34  1  0.618  0.914  0.183  1.0
  O  O35  1  0.614  0.576  0.516  1.0
  O  O36  1  0.886  0.576  0.516  1.0
  O  O37  1  0.066  0.978  0.397  1.0
  O  O38  1  0.433  0.650  0.729  1.0
  O  O39  1  0.434  0.978  0.397  1.0
  O  O40  1  0.067  0.650  0.729  1.0
  O  O41  1  0.250  0.871  0.580  1.0
  O  O42  1  0.750  0.129  0.420  1.0
  O  O43  1  0.750  0.796  0.759  1.0
  O  O44  1  0.934  0.022  0.603  1.0
  O  O45  1  0.566  0.022  0.603  1.0
  O  O46  1  0.382  0.086  0.817  1.0
  O  O47  1  0.118  0.086  0.817  1.0
[/CIF]
.
The compound described by Mg2Ti7O15 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form distorted MgO6 octahedra that share  a cornercorner with one Mg(2)O6 octahedra, corners with two equivalent Ti(3)O6 octahedra, edges with two equivalent Ti(3)O6 octahedra, and edges with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-46°. In the second Mg site, Mg(2) is bonded to one O(3), one O(9), two equivalent O(6), and two equivalent O(8) atoms to form distorted MgO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, edges with two equivalent Ti(3)O6 octahedra, and edges with four equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-46°. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(4), one O(5), one O(7), and two equivalent O(2) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(3)O6 octahedra,  an edgeedge with one Ti(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-48°. In the second Ti site, Ti(2) is bonded to one O(5), one O(9), two equivalent O(6), and two equivalent O(8) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(3)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-51°. In the third Ti site, Ti(3) is bonded to one O(1), one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form distorted TiO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-49°. In the fourth Ti site, Ti(4) is bonded in a 6-coordinate geometry to one O(4), one O(9), two equivalent O(5), and two equivalent O(7) atoms. There are nine inequivalent O sites. In the first O site, O(7) is bonded in a distorted T-shaped geometry to one Ti(1), one Ti(3), and one Ti(4) atom. In the second O site, O(8) is bonded to one Mg(2), one Ti(3), and two equivalent Ti(2) atoms to form OMgTi3 trigonal pyramids that share  a cornercorner with one O(2)MgTi3 trigonal pyramid,  a cornercorner with one O(8)MgTi3 trigonal pyramid,  a cornercorner with one O(9)MgTi3 trigonal pyramid,  a cornercorner with one O(5)Ti4 trigonal pyramid,  an edgeedge with one O(3)Mg2Ti2 trigonal pyramid,  an edgeedge with one O(8)MgTi3 trigonal pyramid,  an edgeedge with one O(9)MgTi3 trigonal pyramid, and  an edgeedge with one O(5)Ti4 trigonal pyramid. In the third O site, O(9) is bonded to one Mg(2), one Ti(4), and two equivalent Ti(2) atoms to form distorted OMgTi3 trigonal pyramids that share  a cornercorner with one O(3)Mg2Ti2 trigonal pyramid,  a cornercorner with one O(4)MgTi3 trigonal pyramid, corners with two equivalent O(8)MgTi3 trigonal pyramids, edges with two equivalent O(8)MgTi3 trigonal pyramids, and edges with two equivalent O(5)Ti4 trigonal pyramids. In the fourth O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Ti(1), and one Ti(3) atom. In the fifth O site, O(2) is bonded to one Mg(1), one Ti(3), and two equivalent Ti(1) atoms to form OMgTi3 trigonal pyramids that share  a cornercorner with one O(2)MgTi3 trigonal pyramid,  a cornercorner with one O(4)MgTi3 trigonal pyramid,  a cornercorner with one O(8)MgTi3 trigonal pyramid,  a cornercorner with one O(5)Ti4 trigonal pyramid,  an edgeedge with one O(3)Mg2Ti2 trigonal pyramid,  an edgeedge with one O(2)MgTi3 trigonal pyramid,  an edgeedge with one O(4)MgTi3 trigonal pyramid, and  an edgeedge with one O(5)Ti4 trigonal pyramid. In the sixth O site, O(3) is bonded to one Mg(1), one Mg(2), and two equivalent Ti(3) atoms to form distorted OMg2Ti2 trigonal pyramids that share  a cornercorner with one O(4)MgTi3 trigonal pyramid,  a cornercorner with one O(9)MgTi3 trigonal pyramid, corners with two equivalent O(5)Ti4 trigonal pyramids, edges with two equivalent O(2)MgTi3 trigonal pyramids, and edges with two equivalent O(8)MgTi3 trigonal pyramids. In the seventh O site, O(4) is bonded to one Mg(1), one Ti(4), and two equivalent Ti(1) atoms to form distorted OMgTi3 trigonal pyramids that share  a cornercorner with one O(3)Mg2Ti2 trigonal pyramid,  a cornercorner with one O(9)MgTi3 trigonal pyramid, corners with two equivalent O(2)MgTi3 trigonal pyramids, edges with two equivalent O(2)MgTi3 trigonal pyramids, and edges with two equivalent O(5)Ti4 trigonal pyramids. In the eighth O site, O(5) is bonded to one Ti(1), one Ti(2), one Ti(3), and one Ti(4) atom to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(3)Mg2Ti2 trigonal pyramid,  a cornercorner with one O(2)MgTi3 trigonal pyramid,  a cornercorner with one O(8)MgTi3 trigonal pyramid,  a cornercorner with one O(5)Ti4 trigonal pyramid,  an edgeedge with one O(2)MgTi3 trigonal pyramid,  an edgeedge with one O(4)MgTi3 trigonal pyramid,  an edgeedge with one O(8)MgTi3 trigonal pyramid, and  an edgeedge with one O(9)MgTi3 trigonal pyramid. In the ninth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(2) and two equivalent Ti(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2Ti7O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.001
_cell_length_b   5.216
_cell_length_c   10.620
_cell_angle_alpha   83.861
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   550.818
_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  0.750  0.491  0.898  1.0
  Mg  Mg1  1  0.250  0.509  0.102  1.0
  Mg  Mg2  1  0.250  0.175  0.435  1.0
  Mg  Mg3  1  0.750  0.825  0.565  1.0
  Ti  Ti4  1  0.062  0.393  0.880  1.0
  Ti  Ti5  1  0.438  0.393  0.880  1.0
  Ti  Ti6  1  0.562  0.607  0.120  1.0
  Ti  Ti7  1  0.938  0.607  0.120  1.0
  Ti  Ti8  1  0.563  0.275  0.457  1.0
  Ti  Ti9  1  0.937  0.275  0.457  1.0
  Ti  Ti10  1  0.069  0.060  0.213  1.0
  Ti  Ti11  1  0.431  0.060  0.213  1.0
  Ti  Ti12  1  0.063  0.725  0.543  1.0
  Ti  Ti13  1  0.437  0.725  0.543  1.0
  Ti  Ti14  1  0.750  0.158  0.231  1.0
  Ti  Ti15  1  0.250  0.842  0.769  1.0
  Ti  Ti16  1  0.931  0.940  0.787  1.0
  Ti  Ti17  1  0.569  0.940  0.787  1.0
  O  O18  1  0.888  0.242  0.848  1.0
  O  O19  1  0.612  0.242  0.848  1.0
  O  O20  1  0.435  0.314  0.063  1.0
  O  O21  1  0.065  0.314  0.063  1.0
  O  O22  1  0.250  0.204  0.241  1.0
  O  O23  1  0.250  0.541  0.904  1.0
  O  O24  1  0.750  0.459  0.096  1.0
  O  O25  1  0.935  0.686  0.937  1.0
  O  O26  1  0.567  0.350  0.271  1.0
  O  O27  1  0.933  0.350  0.271  1.0
  O  O28  1  0.565  0.686  0.937  1.0
  O  O29  1  0.388  0.758  0.152  1.0
  O  O30  1  0.386  0.424  0.484  1.0
  O  O31  1  0.112  0.758  0.152  1.0
  O  O32  1  0.114  0.424  0.484  1.0
  O  O33  1  0.882  0.914  0.183  1.0
  O  O34  1  0.618  0.914  0.183  1.0
  O  O35  1  0.614  0.576  0.516  1.0
  O  O36  1  0.886  0.576  0.516  1.0
  O  O37  1  0.066  0.978  0.397  1.0
  O  O38  1  0.433  0.650  0.729  1.0
  O  O39  1  0.434  0.978  0.397  1.0
  O  O40  1  0.067  0.650  0.729  1.0
  O  O41  1  0.250  0.871  0.580  1.0
  O  O42  1  0.750  0.129  0.420  1.0
  O  O43  1  0.750  0.796  0.759  1.0
  O  O44  1  0.934  0.022  0.603  1.0
  O  O45  1  0.566  0.022  0.603  1.0
  O  O46  1  0.382  0.086  0.817  1.0
  O  O47  1  0.118  0.086  0.817  1.0
[/CIF]
.