The material structure described by CaSnP2O7 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form CaO5 trigonal bipyramids that share  a cornercorner with one Sn(1)O5 square pyramid, corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Sn(1)O5 square pyramid. Sn(1) is bonded to one O(5), one O(6), one O(7), and two equivalent O(4) atoms to form distorted SnO5 square pyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra,  a cornercorner with one Ca(1)O5 trigonal bipyramid,  an edgeedge with one Sn(1)O5 square pyramid, and  an edgeedge with one Ca(1)O5 trigonal bipyramid. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Sn(1)O5 square pyramids,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent Ca(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O5 square pyramids,  a cornercorner with one P(1)O4 tetrahedra, and corners with three equivalent Ca(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ca(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Sn(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), one Sn(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(1), one Sn(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ca(1), one Sn(1), and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaSnP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.734
_cell_length_b   7.610
_cell_length_c   9.599
_cell_angle_alpha   66.540
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   652.261
_cell_formula_units_Z   4
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
  Ca  Ca0  1  0.948  0.289  0.822  1.0
  Ca  Ca1  1  0.448  0.711  0.678  1.0
  Ca  Ca2  1  0.552  0.289  0.322  1.0
  Ca  Ca3  1  0.052  0.711  0.178  1.0
  Sn  Sn4  1  0.082  0.766  0.608  1.0
  Sn  Sn5  1  0.918  0.234  0.392  1.0
  Sn  Sn6  1  0.582  0.234  0.892  1.0
  Sn  Sn7  1  0.418  0.766  0.108  1.0
  P  P8  1  0.739  0.931  0.255  1.0
  P  P9  1  0.223  0.469  0.973  1.0
  P  P10  1  0.761  0.931  0.755  1.0
  P  P11  1  0.277  0.469  0.473  1.0
  P  P12  1  0.239  0.069  0.245  1.0
  P  P13  1  0.723  0.531  0.527  1.0
  P  P14  1  0.777  0.531  0.027  1.0
  P  P15  1  0.261  0.069  0.745  1.0
  O  O16  1  0.191  0.254  0.096  1.0
  O  O17  1  0.622  0.893  0.700  1.0
  O  O18  1  0.878  0.893  0.200  1.0
  O  O19  1  0.365  0.479  0.902  1.0
  O  O20  1  0.809  0.746  0.904  1.0
  O  O21  1  0.120  0.032  0.358  1.0
  O  O22  1  0.635  0.521  0.098  1.0
  O  O23  1  0.103  0.500  0.861  1.0
  O  O24  1  0.285  0.604  0.557  1.0
  O  O25  1  0.880  0.968  0.642  1.0
  O  O26  1  0.380  0.032  0.858  1.0
  O  O27  1  0.757  0.095  0.813  1.0
  O  O28  1  0.257  0.905  0.687  1.0
  O  O29  1  0.309  0.254  0.596  1.0
  O  O30  1  0.620  0.968  0.142  1.0
  O  O31  1  0.122  0.107  0.800  1.0
  O  O32  1  0.243  0.905  0.187  1.0
  O  O33  1  0.897  0.500  0.139  1.0
  O  O34  1  0.215  0.604  0.057  1.0
  O  O35  1  0.785  0.396  0.943  1.0
  O  O36  1  0.865  0.521  0.598  1.0
  O  O37  1  0.397  0.500  0.361  1.0
  O  O38  1  0.603  0.500  0.639  1.0
  O  O39  1  0.378  0.107  0.300  1.0
  O  O40  1  0.743  0.095  0.313  1.0
  O  O41  1  0.135  0.479  0.402  1.0
  O  O42  1  0.715  0.396  0.443  1.0
  O  O43  1  0.691  0.746  0.404  1.0
[/CIF]
.
The material structure described by CaSnP2O7 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form CaO5 trigonal bipyramids that share  a cornercorner with one Sn(1)O5 square pyramid, corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Sn(1)O5 square pyramid. Sn(1) is bonded to one O(5), one O(6), one O(7), and two equivalent O(4) atoms to form distorted SnO5 square pyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra,  a cornercorner with one Ca(1)O5 trigonal bipyramid,  an edgeedge with one Sn(1)O5 square pyramid, and  an edgeedge with one Ca(1)O5 trigonal bipyramid. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Sn(1)O5 square pyramids,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent Ca(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O5 square pyramids,  a cornercorner with one P(1)O4 tetrahedra, and corners with three equivalent Ca(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ca(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Sn(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), one Sn(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(1), one Sn(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ca(1), one Sn(1), and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaSnP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.734
_cell_length_b   7.610
_cell_length_c   9.599
_cell_angle_alpha   66.540
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   652.261
_cell_formula_units_Z   4
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
  Ca  Ca0  1  0.948  0.289  0.822  1.0
  Ca  Ca1  1  0.448  0.711  0.678  1.0
  Ca  Ca2  1  0.552  0.289  0.322  1.0
  Ca  Ca3  1  0.052  0.711  0.178  1.0
  Sn  Sn4  1  0.082  0.766  0.608  1.0
  Sn  Sn5  1  0.918  0.234  0.392  1.0
  Sn  Sn6  1  0.582  0.234  0.892  1.0
  Sn  Sn7  1  0.418  0.766  0.108  1.0
  P  P8  1  0.739  0.931  0.255  1.0
  P  P9  1  0.223  0.469  0.973  1.0
  P  P10  1  0.761  0.931  0.755  1.0
  P  P11  1  0.277  0.469  0.473  1.0
  P  P12  1  0.239  0.069  0.245  1.0
  P  P13  1  0.723  0.531  0.527  1.0
  P  P14  1  0.777  0.531  0.027  1.0
  P  P15  1  0.261  0.069  0.745  1.0
  O  O16  1  0.191  0.254  0.096  1.0
  O  O17  1  0.622  0.893  0.700  1.0
  O  O18  1  0.878  0.893  0.200  1.0
  O  O19  1  0.365  0.479  0.902  1.0
  O  O20  1  0.809  0.746  0.904  1.0
  O  O21  1  0.120  0.032  0.358  1.0
  O  O22  1  0.635  0.521  0.098  1.0
  O  O23  1  0.103  0.500  0.861  1.0
  O  O24  1  0.285  0.604  0.557  1.0
  O  O25  1  0.880  0.968  0.642  1.0
  O  O26  1  0.380  0.032  0.858  1.0
  O  O27  1  0.757  0.095  0.813  1.0
  O  O28  1  0.257  0.905  0.687  1.0
  O  O29  1  0.309  0.254  0.596  1.0
  O  O30  1  0.620  0.968  0.142  1.0
  O  O31  1  0.122  0.107  0.800  1.0
  O  O32  1  0.243  0.905  0.187  1.0
  O  O33  1  0.897  0.500  0.139  1.0
  O  O34  1  0.215  0.604  0.057  1.0
  O  O35  1  0.785  0.396  0.943  1.0
  O  O36  1  0.865  0.521  0.598  1.0
  O  O37  1  0.397  0.500  0.361  1.0
  O  O38  1  0.603  0.500  0.639  1.0
  O  O39  1  0.378  0.107  0.300  1.0
  O  O40  1  0.743  0.095  0.313  1.0
  O  O41  1  0.135  0.479  0.402  1.0
  O  O42  1  0.715  0.396  0.443  1.0
  O  O43  1  0.691  0.746  0.404  1.0
[/CIF]
.