The compound described by Mg3Ti2O7 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(2), and three equivalent O(1) atoms. Ti(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 36-45°. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Mg(2) and one Ti(1) atom to form OMg3Ti tetrahedra that share  a cornercorner with one O(4)Mg2Ti2 tetrahedra and corners with six equivalent O(1)Mg3Ti tetrahedra. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(2), and two equivalent Ti(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Mg(2), and two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1) and two equivalent Ti(1) atoms to form distorted OMg2Ti2 tetrahedra that share corners with two equivalent O(4)Mg2Ti2 tetrahedra and corners with two equivalent O(1)Mg3Ti tetrahedra. is represented by the CIF card [CIF]
data_Mg3Ti2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.315
_cell_length_b   9.315
_cell_length_c   5.363
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   147.589
_symmetry_Int_Tables_number   1
_cell_volume   249.407
_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  0.254  0.254  0.296  1.0
  Mg  Mg1  1  0.746  0.746  0.796  1.0
  Mg  Mg2  1  0.036  0.424  0.185  1.0
  Mg  Mg3  1  0.964  0.576  0.685  1.0
  Mg  Mg4  1  0.424  0.036  0.185  1.0
  Mg  Mg5  1  0.576  0.964  0.685  1.0
  Ti  Ti6  1  0.858  0.647  0.236  1.0
  Ti  Ti7  1  0.142  0.353  0.736  1.0
  Ti  Ti8  1  0.353  0.142  0.736  1.0
  Ti  Ti9  1  0.647  0.858  0.236  1.0
  O  O10  1  0.653  0.066  0.307  1.0
  O  O11  1  0.347  0.934  0.807  1.0
  O  O12  1  0.934  0.347  0.807  1.0
  O  O13  1  0.066  0.653  0.307  1.0
  O  O14  1  0.440  0.700  0.941  1.0
  O  O15  1  0.560  0.300  0.441  1.0
  O  O16  1  0.300  0.560  0.441  1.0
  O  O17  1  0.700  0.440  0.941  1.0
  O  O18  1  0.993  0.153  0.076  1.0
  O  O19  1  0.007  0.847  0.576  1.0
  O  O20  1  0.633  0.633  0.193  1.0
  O  O21  1  0.367  0.367  0.693  1.0
  O  O22  1  0.153  0.993  0.076  1.0
  O  O23  1  0.847  0.007  0.576  1.0
[/CIF]
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The compound described by Mg3Ti2O7 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(2), and three equivalent O(1) atoms. Ti(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 36-45°. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Mg(2) and one Ti(1) atom to form OMg3Ti tetrahedra that share  a cornercorner with one O(4)Mg2Ti2 tetrahedra and corners with six equivalent O(1)Mg3Ti tetrahedra. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(2), and two equivalent Ti(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Mg(2), and two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1) and two equivalent Ti(1) atoms to form distorted OMg2Ti2 tetrahedra that share corners with two equivalent O(4)Mg2Ti2 tetrahedra and corners with two equivalent O(1)Mg3Ti tetrahedra. is represented by the CIF card [CIF]
data_Mg3Ti2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.315
_cell_length_b   9.315
_cell_length_c   5.363
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   147.589
_symmetry_Int_Tables_number   1
_cell_volume   249.407
_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  0.254  0.254  0.296  1.0
  Mg  Mg1  1  0.746  0.746  0.796  1.0
  Mg  Mg2  1  0.036  0.424  0.185  1.0
  Mg  Mg3  1  0.964  0.576  0.685  1.0
  Mg  Mg4  1  0.424  0.036  0.185  1.0
  Mg  Mg5  1  0.576  0.964  0.685  1.0
  Ti  Ti6  1  0.858  0.647  0.236  1.0
  Ti  Ti7  1  0.142  0.353  0.736  1.0
  Ti  Ti8  1  0.353  0.142  0.736  1.0
  Ti  Ti9  1  0.647  0.858  0.236  1.0
  O  O10  1  0.653  0.066  0.307  1.0
  O  O11  1  0.347  0.934  0.807  1.0
  O  O12  1  0.934  0.347  0.807  1.0
  O  O13  1  0.066  0.653  0.307  1.0
  O  O14  1  0.440  0.700  0.941  1.0
  O  O15  1  0.560  0.300  0.441  1.0
  O  O16  1  0.300  0.560  0.441  1.0
  O  O17  1  0.700  0.440  0.941  1.0
  O  O18  1  0.993  0.153  0.076  1.0
  O  O19  1  0.007  0.847  0.576  1.0
  O  O20  1  0.633  0.633  0.193  1.0
  O  O21  1  0.367  0.367  0.693  1.0
  O  O22  1  0.153  0.993  0.076  1.0
  O  O23  1  0.847  0.007  0.576  1.0
[/CIF]
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