The structure described by Li3CuP2O7 crystallizes in the triclinic P-1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(6), and two equivalent O(7) atoms to form LiO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. In the third Li site, Li(3) is bonded in a 3-coordinate geometry to one O(1), one O(4), and one O(7) atom. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to two equivalent O(3) and two equivalent O(6) atoms. In the second Cu site, Cu(2) is bonded in a distorted square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent Li(2)O4 tetrahedra. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with three equivalent Li(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Li(3), one Cu(2), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Li(2) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Cu(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(2), one Li(3), one Cu(2), and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(1), one Cu(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Li(3), two equivalent Li(1), and one P(2) atom. is represented by the CIF file [CIF]
data_Li3CuP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.155
_cell_length_b   7.872
_cell_length_c   9.017
_cell_angle_alpha   109.918
_cell_angle_beta   92.301
_cell_angle_gamma   108.746
_symmetry_Int_Tables_number   1
_cell_volume   321.182
_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
  Li  Li0  1  0.061  0.864  0.546  1.0
  Li  Li1  1  0.658  0.133  0.974  1.0
  Li  Li2  1  0.015  0.187  0.802  1.0
  Li  Li3  1  0.985  0.813  0.198  1.0
  Li  Li4  1  0.342  0.867  0.026  1.0
  Li  Li5  1  0.939  0.136  0.454  1.0
  Cu  Cu6  1  0.000  0.500  0.500  1.0
  Cu  Cu7  1  0.000  0.500  0.000  1.0
  P  P8  1  0.747  0.717  0.820  1.0
  P  P9  1  0.533  0.287  0.680  1.0
  P  P10  1  0.467  0.713  0.320  1.0
  P  P11  1  0.253  0.283  0.180  1.0
  O  O12  1  0.936  0.726  0.964  1.0
  O  O13  1  0.593  0.857  0.878  1.0
  O  O14  1  0.900  0.737  0.683  1.0
  O  O15  1  0.676  0.254  0.816  1.0
  O  O16  1  0.508  0.500  0.756  1.0
  O  O17  1  0.298  0.721  0.456  1.0
  O  O18  1  0.225  0.152  0.630  1.0
  O  O19  1  0.775  0.848  0.370  1.0
  O  O20  1  0.702  0.279  0.544  1.0
  O  O21  1  0.492  0.500  0.244  1.0
  O  O22  1  0.324  0.746  0.184  1.0
  O  O23  1  0.100  0.263  0.317  1.0
  O  O24  1  0.407  0.143  0.122  1.0
  O  O25  1  0.064  0.274  0.036  1.0
[/CIF]
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The structure described by Li3CuP2O7 crystallizes in the triclinic P-1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(6), and two equivalent O(7) atoms to form LiO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. In the third Li site, Li(3) is bonded in a 3-coordinate geometry to one O(1), one O(4), and one O(7) atom. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to two equivalent O(3) and two equivalent O(6) atoms. In the second Cu site, Cu(2) is bonded in a distorted square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent Li(2)O4 tetrahedra. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with three equivalent Li(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Li(3), one Cu(2), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Li(2) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Cu(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(2), one Li(3), one Cu(2), and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(1), one Cu(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Li(3), two equivalent Li(1), and one P(2) atom. is represented by the CIF file [CIF]
data_Li3CuP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.155
_cell_length_b   7.872
_cell_length_c   9.017
_cell_angle_alpha   109.918
_cell_angle_beta   92.301
_cell_angle_gamma   108.746
_symmetry_Int_Tables_number   1
_cell_volume   321.182
_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
  Li  Li0  1  0.061  0.864  0.546  1.0
  Li  Li1  1  0.658  0.133  0.974  1.0
  Li  Li2  1  0.015  0.187  0.802  1.0
  Li  Li3  1  0.985  0.813  0.198  1.0
  Li  Li4  1  0.342  0.867  0.026  1.0
  Li  Li5  1  0.939  0.136  0.454  1.0
  Cu  Cu6  1  0.000  0.500  0.500  1.0
  Cu  Cu7  1  0.000  0.500  0.000  1.0
  P  P8  1  0.747  0.717  0.820  1.0
  P  P9  1  0.533  0.287  0.680  1.0
  P  P10  1  0.467  0.713  0.320  1.0
  P  P11  1  0.253  0.283  0.180  1.0
  O  O12  1  0.936  0.726  0.964  1.0
  O  O13  1  0.593  0.857  0.878  1.0
  O  O14  1  0.900  0.737  0.683  1.0
  O  O15  1  0.676  0.254  0.816  1.0
  O  O16  1  0.508  0.500  0.756  1.0
  O  O17  1  0.298  0.721  0.456  1.0
  O  O18  1  0.225  0.152  0.630  1.0
  O  O19  1  0.775  0.848  0.370  1.0
  O  O20  1  0.702  0.279  0.544  1.0
  O  O21  1  0.492  0.500  0.244  1.0
  O  O22  1  0.324  0.746  0.184  1.0
  O  O23  1  0.100  0.263  0.317  1.0
  O  O24  1  0.407  0.143  0.122  1.0
  O  O25  1  0.064  0.274  0.036  1.0
[/CIF]
.