The structure described by MgSn3P3O13 crystallizes in the monoclinic P2_1/m space group. Mg(1) is bonded in a 5-coordinate geometry to one O(9), two equivalent O(2), and two equivalent O(8) atoms. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(1), one O(5), one O(6), one O(7), and two equivalent O(8) atoms to form SnO6 octahedra that share corners with two equivalent Sn(3)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. In the second Sn site, Sn(2) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(7), and two equivalent O(2) atoms. In the third Sn site, Sn(3) is bonded to two equivalent O(10), two equivalent O(4), and two equivalent O(6) atoms to form SnO6 octahedra that share corners with two equivalent Sn(1)O6 octahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and edges with two equivalent Sn(3)O6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(5), one O(7), and two equivalent O(2) atoms to form PO4 tetrahedra that share  an edgeedge with one Sn(1)O6 octahedra. In the second P site, P(2) is bonded to one O(10), one O(3), and two equivalent O(8) atoms to form PO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra and corners with two equivalent Sn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-52°. In the third P site, P(3) is bonded to one O(1), one O(9), and two equivalent O(4) atoms to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O6 octahedra and corners with two equivalent Sn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-52°. There are ten inequivalent O sites. In the first O site, O(10) is bonded in a 3-coordinate geometry to two equivalent Sn(3) and one P(2) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Sn(1), one Sn(2), and one P(3) atom. In the third O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Sn(2), and one P(1) atom. In the fourth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Sn(2) and one P(2) atom. In the fifth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Sn(3) and one P(3) atom. In the sixth O site, O(5) is bonded in a distorted water-like geometry to one Sn(1) and one P(1) atom. In the seventh O site, O(6) is bonded in a trigonal planar geometry to one Sn(1) and two equivalent Sn(3) atoms. In the eighth O site, O(7) is bonded in a 3-coordinate geometry to one Sn(1), one Sn(2), and one P(1) atom. In the ninth O site, O(8) is bonded in a 3-coordinate geometry to one Mg(1), one Sn(1), and one P(2) atom. In the tenth O site, O(9) is bonded in a bent 150 degrees geometry to one Mg(1) and one P(3) atom. is represented by the CIF file [CIF]
data_MgSn3P3O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.821
_cell_length_b   7.867
_cell_length_c   10.490
_cell_angle_alpha   82.418
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   558.002
_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  0.436  0.225  1.0
  Mg  Mg1  1  0.250  0.564  0.775  1.0
  Sn  Sn2  1  0.250  0.684  0.257  1.0
  Sn  Sn3  1  0.750  0.316  0.743  1.0
  Sn  Sn4  1  0.250  0.197  0.393  1.0
  Sn  Sn5  1  0.500  0.000  0.000  1.0
  Sn  Sn6  1  0.750  0.803  0.607  1.0
  Sn  Sn7  1  0.000  0.000  0.000  1.0
  P  P8  1  0.250  0.695  0.523  1.0
  P  P9  1  0.750  0.305  0.477  1.0
  P  P10  1  0.250  0.210  0.730  1.0
  P  P11  1  0.750  0.790  0.270  1.0
  P  P12  1  0.750  0.649  0.927  1.0
  P  P13  1  0.250  0.351  0.073  1.0
  O  O14  1  0.750  0.554  0.802  1.0
  O  O15  1  0.575  0.311  0.383  1.0
  O  O16  1  0.250  0.127  0.608  1.0
  O  O17  1  0.563  0.764  0.913  1.0
  O  O18  1  0.750  0.460  0.558  1.0
  O  O19  1  0.750  0.124  0.894  1.0
  O  O20  1  0.250  0.540  0.442  1.0
  O  O21  1  0.063  0.236  0.087  1.0
  O  O22  1  0.250  0.849  0.411  1.0
  O  O23  1  0.750  0.151  0.589  1.0
  O  O24  1  0.071  0.333  0.741  1.0
  O  O25  1  0.250  0.876  0.106  1.0
  O  O26  1  0.571  0.667  0.259  1.0
  O  O27  1  0.750  0.516  0.045  1.0
  O  O28  1  0.750  0.873  0.392  1.0
  O  O29  1  0.437  0.236  0.087  1.0
  O  O30  1  0.925  0.311  0.383  1.0
  O  O31  1  0.425  0.689  0.617  1.0
  O  O32  1  0.429  0.333  0.741  1.0
  O  O33  1  0.250  0.446  0.198  1.0
  O  O34  1  0.750  0.932  0.147  1.0
  O  O35  1  0.250  0.068  0.853  1.0
  O  O36  1  0.929  0.667  0.259  1.0
  O  O37  1  0.937  0.764  0.913  1.0
  O  O38  1  0.075  0.689  0.617  1.0
  O  O39  1  0.250  0.484  0.955  1.0
[/CIF]
.
The structure described by MgSn3P3O13 crystallizes in the monoclinic P2_1/m space group. Mg(1) is bonded in a 5-coordinate geometry to one O(9), two equivalent O(2), and two equivalent O(8) atoms. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(1), one O(5), one O(6), one O(7), and two equivalent O(8) atoms to form SnO6 octahedra that share corners with two equivalent Sn(3)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. In the second Sn site, Sn(2) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(7), and two equivalent O(2) atoms. In the third Sn site, Sn(3) is bonded to two equivalent O(10), two equivalent O(4), and two equivalent O(6) atoms to form SnO6 octahedra that share corners with two equivalent Sn(1)O6 octahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and edges with two equivalent Sn(3)O6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(5), one O(7), and two equivalent O(2) atoms to form PO4 tetrahedra that share  an edgeedge with one Sn(1)O6 octahedra. In the second P site, P(2) is bonded to one O(10), one O(3), and two equivalent O(8) atoms to form PO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra and corners with two equivalent Sn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-52°. In the third P site, P(3) is bonded to one O(1), one O(9), and two equivalent O(4) atoms to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O6 octahedra and corners with two equivalent Sn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-52°. There are ten inequivalent O sites. In the first O site, O(10) is bonded in a 3-coordinate geometry to two equivalent Sn(3) and one P(2) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Sn(1), one Sn(2), and one P(3) atom. In the third O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Sn(2), and one P(1) atom. In the fourth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Sn(2) and one P(2) atom. In the fifth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Sn(3) and one P(3) atom. In the sixth O site, O(5) is bonded in a distorted water-like geometry to one Sn(1) and one P(1) atom. In the seventh O site, O(6) is bonded in a trigonal planar geometry to one Sn(1) and two equivalent Sn(3) atoms. In the eighth O site, O(7) is bonded in a 3-coordinate geometry to one Sn(1), one Sn(2), and one P(1) atom. In the ninth O site, O(8) is bonded in a 3-coordinate geometry to one Mg(1), one Sn(1), and one P(2) atom. In the tenth O site, O(9) is bonded in a bent 150 degrees geometry to one Mg(1) and one P(3) atom. is represented by the CIF file [CIF]
data_MgSn3P3O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.821
_cell_length_b   7.867
_cell_length_c   10.490
_cell_angle_alpha   82.418
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   558.002
_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  0.436  0.225  1.0
  Mg  Mg1  1  0.250  0.564  0.775  1.0
  Sn  Sn2  1  0.250  0.684  0.257  1.0
  Sn  Sn3  1  0.750  0.316  0.743  1.0
  Sn  Sn4  1  0.250  0.197  0.393  1.0
  Sn  Sn5  1  0.500  0.000  0.000  1.0
  Sn  Sn6  1  0.750  0.803  0.607  1.0
  Sn  Sn7  1  0.000  0.000  0.000  1.0
  P  P8  1  0.250  0.695  0.523  1.0
  P  P9  1  0.750  0.305  0.477  1.0
  P  P10  1  0.250  0.210  0.730  1.0
  P  P11  1  0.750  0.790  0.270  1.0
  P  P12  1  0.750  0.649  0.927  1.0
  P  P13  1  0.250  0.351  0.073  1.0
  O  O14  1  0.750  0.554  0.802  1.0
  O  O15  1  0.575  0.311  0.383  1.0
  O  O16  1  0.250  0.127  0.608  1.0
  O  O17  1  0.563  0.764  0.913  1.0
  O  O18  1  0.750  0.460  0.558  1.0
  O  O19  1  0.750  0.124  0.894  1.0
  O  O20  1  0.250  0.540  0.442  1.0
  O  O21  1  0.063  0.236  0.087  1.0
  O  O22  1  0.250  0.849  0.411  1.0
  O  O23  1  0.750  0.151  0.589  1.0
  O  O24  1  0.071  0.333  0.741  1.0
  O  O25  1  0.250  0.876  0.106  1.0
  O  O26  1  0.571  0.667  0.259  1.0
  O  O27  1  0.750  0.516  0.045  1.0
  O  O28  1  0.750  0.873  0.392  1.0
  O  O29  1  0.437  0.236  0.087  1.0
  O  O30  1  0.925  0.311  0.383  1.0
  O  O31  1  0.425  0.689  0.617  1.0
  O  O32  1  0.429  0.333  0.741  1.0
  O  O33  1  0.250  0.446  0.198  1.0
  O  O34  1  0.750  0.932  0.147  1.0
  O  O35  1  0.250  0.068  0.853  1.0
  O  O36  1  0.929  0.667  0.259  1.0
  O  O37  1  0.937  0.764  0.913  1.0
  O  O38  1  0.075  0.689  0.617  1.0
  O  O39  1  0.250  0.484  0.955  1.0
[/CIF]
.