The structure described by Li2SnP2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form distorted LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  a cornercorner with one Li(2)O5 trigonal bipyramid. In the second Li site, Li(2) is bonded to one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Li(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and corners with two equivalent Li(2)O5 trigonal bipyramids. Sn(1) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), one O(6), and one O(7) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent Li(2)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent Li(2)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Li(1) and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Sn(1), and one P(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Sn(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to two equivalent Li(2) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(2), 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 Li(2), one Sn(1), and one P(2) atom. is represented by the CIF file [CIF]
data_Li2SnP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.094
_cell_length_b   8.694
_cell_length_c   15.087
_cell_angle_alpha   68.639
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   622.340
_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
  Li  Li0  1  0.251  0.995  0.679  1.0
  Li  Li1  1  0.249  0.995  0.179  1.0
  Li  Li2  1  0.732  0.412  0.825  1.0
  Li  Li3  1  0.232  0.588  0.675  1.0
  Li  Li4  1  0.768  0.412  0.325  1.0
  Li  Li5  1  0.268  0.588  0.175  1.0
  Li  Li6  1  0.751  0.005  0.821  1.0
  Li  Li7  1  0.749  0.005  0.321  1.0
  Sn  Sn8  1  0.275  0.715  0.885  1.0
  Sn  Sn9  1  0.225  0.715  0.385  1.0
  Sn  Sn10  1  0.775  0.285  0.615  1.0
  Sn  Sn11  1  0.725  0.285  0.115  1.0
  P  P12  1  0.759  0.787  0.702  1.0
  P  P13  1  0.722  0.701  0.534  1.0
  P  P14  1  0.741  0.787  0.202  1.0
  P  P15  1  0.222  0.299  0.966  1.0
  P  P16  1  0.778  0.701  0.034  1.0
  P  P17  1  0.259  0.213  0.798  1.0
  P  P18  1  0.278  0.299  0.466  1.0
  P  P19  1  0.241  0.213  0.298  1.0
  O  O20  1  0.382  0.063  0.784  1.0
  O  O21  1  0.118  0.063  0.284  1.0
  O  O22  1  0.695  0.790  0.930  1.0
  O  O23  1  0.796  0.829  0.587  1.0
  O  O24  1  0.459  0.776  0.720  1.0
  O  O25  1  0.904  0.626  0.754  1.0
  O  O26  1  0.428  0.665  0.546  1.0
  O  O27  1  0.805  0.790  0.430  1.0
  O  O28  1  0.704  0.829  0.087  1.0
  O  O29  1  0.395  0.453  0.918  1.0
  O  O30  1  0.041  0.776  0.220  1.0
  O  O31  1  0.596  0.626  0.254  1.0
  O  O32  1  0.895  0.547  0.582  1.0
  O  O33  1  0.072  0.665  0.046  1.0
  O  O34  1  0.928  0.335  0.954  1.0
  O  O35  1  0.105  0.453  0.418  1.0
  O  O36  1  0.404  0.374  0.746  1.0
  O  O37  1  0.959  0.224  0.780  1.0
  O  O38  1  0.605  0.547  0.082  1.0
  O  O39  1  0.296  0.171  0.913  1.0
  O  O40  1  0.195  0.210  0.570  1.0
  O  O41  1  0.572  0.335  0.454  1.0
  O  O42  1  0.096  0.374  0.246  1.0
  O  O43  1  0.541  0.224  0.280  1.0
  O  O44  1  0.204  0.171  0.413  1.0
  O  O45  1  0.305  0.210  0.070  1.0
  O  O46  1  0.882  0.937  0.716  1.0
  O  O47  1  0.618  0.937  0.216  1.0
[/CIF]
.
The structure described by Li2SnP2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form distorted LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  a cornercorner with one Li(2)O5 trigonal bipyramid. In the second Li site, Li(2) is bonded to one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Li(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and corners with two equivalent Li(2)O5 trigonal bipyramids. Sn(1) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), one O(6), and one O(7) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent Li(2)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent Li(2)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Li(1) and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Sn(1), and one P(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Sn(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to two equivalent Li(2) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(2), 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 Li(2), one Sn(1), and one P(2) atom. is represented by the CIF file [CIF]
data_Li2SnP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.094
_cell_length_b   8.694
_cell_length_c   15.087
_cell_angle_alpha   68.639
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   622.340
_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
  Li  Li0  1  0.251  0.995  0.679  1.0
  Li  Li1  1  0.249  0.995  0.179  1.0
  Li  Li2  1  0.732  0.412  0.825  1.0
  Li  Li3  1  0.232  0.588  0.675  1.0
  Li  Li4  1  0.768  0.412  0.325  1.0
  Li  Li5  1  0.268  0.588  0.175  1.0
  Li  Li6  1  0.751  0.005  0.821  1.0
  Li  Li7  1  0.749  0.005  0.321  1.0
  Sn  Sn8  1  0.275  0.715  0.885  1.0
  Sn  Sn9  1  0.225  0.715  0.385  1.0
  Sn  Sn10  1  0.775  0.285  0.615  1.0
  Sn  Sn11  1  0.725  0.285  0.115  1.0
  P  P12  1  0.759  0.787  0.702  1.0
  P  P13  1  0.722  0.701  0.534  1.0
  P  P14  1  0.741  0.787  0.202  1.0
  P  P15  1  0.222  0.299  0.966  1.0
  P  P16  1  0.778  0.701  0.034  1.0
  P  P17  1  0.259  0.213  0.798  1.0
  P  P18  1  0.278  0.299  0.466  1.0
  P  P19  1  0.241  0.213  0.298  1.0
  O  O20  1  0.382  0.063  0.784  1.0
  O  O21  1  0.118  0.063  0.284  1.0
  O  O22  1  0.695  0.790  0.930  1.0
  O  O23  1  0.796  0.829  0.587  1.0
  O  O24  1  0.459  0.776  0.720  1.0
  O  O25  1  0.904  0.626  0.754  1.0
  O  O26  1  0.428  0.665  0.546  1.0
  O  O27  1  0.805  0.790  0.430  1.0
  O  O28  1  0.704  0.829  0.087  1.0
  O  O29  1  0.395  0.453  0.918  1.0
  O  O30  1  0.041  0.776  0.220  1.0
  O  O31  1  0.596  0.626  0.254  1.0
  O  O32  1  0.895  0.547  0.582  1.0
  O  O33  1  0.072  0.665  0.046  1.0
  O  O34  1  0.928  0.335  0.954  1.0
  O  O35  1  0.105  0.453  0.418  1.0
  O  O36  1  0.404  0.374  0.746  1.0
  O  O37  1  0.959  0.224  0.780  1.0
  O  O38  1  0.605  0.547  0.082  1.0
  O  O39  1  0.296  0.171  0.913  1.0
  O  O40  1  0.195  0.210  0.570  1.0
  O  O41  1  0.572  0.335  0.454  1.0
  O  O42  1  0.096  0.374  0.246  1.0
  O  O43  1  0.541  0.224  0.280  1.0
  O  O44  1  0.204  0.171  0.413  1.0
  O  O45  1  0.305  0.210  0.070  1.0
  O  O46  1  0.882  0.937  0.716  1.0
  O  O47  1  0.618  0.937  0.216  1.0
[/CIF]
.