The material structure described by Li2CuP2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(7), and two equivalent O(5) atoms. In the second Li site, Li(2) is bonded to one O(1), one O(3), one O(4), one O(5), and one O(6) atom to form distorted LiO5 square pyramids that share  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra,  a cornercorner with one Cu(1)O5 trigonal bipyramid,  an edgeedge with one P(2)O4 tetrahedra, and  an edgeedge with one Cu(1)O5 trigonal bipyramid. Cu(1) is bonded to one O(1), one O(4), one O(6), and two equivalent O(2) atoms to form distorted CuO5 trigonal bipyramids that share  a cornercorner with one Li(2)O5 square pyramid,  a cornercorner with one P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra,  an edgeedge with one Li(2)O5 square pyramid, and  an edgeedge with one Cu(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(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Li(2)O5 square pyramids,  a cornercorner with one P(2)O4 tetrahedra, and corners with four equivalent Cu(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O5 square pyramid,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one Cu(1)O5 trigonal bipyramid, and  an edgeedge with one Li(2)O5 square pyramid. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Li(2), one Cu(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Cu(1) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Li(2), 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 Cu(1), and one P(2) atom. In the fifth O site, O(5) is bonded to one Li(2), two equivalent Li(1), and one P(2) atom to form distorted edge-sharing OLi3P trigonal pyramids. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one Cu(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Li(1), one P(1), and one P(2) atom. is represented by the CIF file [CIF]
data_Li2CuP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.309
_cell_length_b   6.271
_cell_length_c   8.890
_cell_angle_alpha   110.289
_cell_angle_beta   91.826
_cell_angle_gamma   105.502
_symmetry_Int_Tables_number   1
_cell_volume   264.947
_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  0.081  0.763  0.013  1.0
  Li  Li1  1  0.328  0.216  0.753  1.0
  Li  Li2  1  0.672  0.784  0.247  1.0
  Li  Li3  1  0.919  0.237  0.987  1.0
  Cu  Cu4  1  0.114  0.607  0.378  1.0
  Cu  Cu5  1  0.886  0.393  0.622  1.0
  P  P6  1  0.232  0.140  0.391  1.0
  P  P7  1  0.592  0.697  0.885  1.0
  P  P8  1  0.408  0.303  0.115  1.0
  P  P9  1  0.768  0.860  0.609  1.0
  O  O10  1  0.059  0.879  0.330  1.0
  O  O11  1  0.045  0.302  0.415  1.0
  O  O12  1  0.297  0.586  0.873  1.0
  O  O13  1  0.260  0.494  0.176  1.0
  O  O14  1  0.264  0.123  0.950  1.0
  O  O15  1  0.561  0.781  0.466  1.0
  O  O16  1  0.628  0.849  0.766  1.0
  O  O17  1  0.372  0.151  0.234  1.0
  O  O18  1  0.439  0.219  0.534  1.0
  O  O19  1  0.736  0.877  0.050  1.0
  O  O20  1  0.740  0.506  0.824  1.0
  O  O21  1  0.703  0.414  0.127  1.0
  O  O22  1  0.955  0.698  0.585  1.0
  O  O23  1  0.941  0.121  0.670  1.0
[/CIF]
.
The material structure described by Li2CuP2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(7), and two equivalent O(5) atoms. In the second Li site, Li(2) is bonded to one O(1), one O(3), one O(4), one O(5), and one O(6) atom to form distorted LiO5 square pyramids that share  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra,  a cornercorner with one Cu(1)O5 trigonal bipyramid,  an edgeedge with one P(2)O4 tetrahedra, and  an edgeedge with one Cu(1)O5 trigonal bipyramid. Cu(1) is bonded to one O(1), one O(4), one O(6), and two equivalent O(2) atoms to form distorted CuO5 trigonal bipyramids that share  a cornercorner with one Li(2)O5 square pyramid,  a cornercorner with one P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra,  an edgeedge with one Li(2)O5 square pyramid, and  an edgeedge with one Cu(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(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Li(2)O5 square pyramids,  a cornercorner with one P(2)O4 tetrahedra, and corners with four equivalent Cu(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O5 square pyramid,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one Cu(1)O5 trigonal bipyramid, and  an edgeedge with one Li(2)O5 square pyramid. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Li(2), one Cu(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Cu(1) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Li(2), 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 Cu(1), and one P(2) atom. In the fifth O site, O(5) is bonded to one Li(2), two equivalent Li(1), and one P(2) atom to form distorted edge-sharing OLi3P trigonal pyramids. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one Cu(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Li(1), one P(1), and one P(2) atom. is represented by the CIF file [CIF]
data_Li2CuP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.309
_cell_length_b   6.271
_cell_length_c   8.890
_cell_angle_alpha   110.289
_cell_angle_beta   91.826
_cell_angle_gamma   105.502
_symmetry_Int_Tables_number   1
_cell_volume   264.947
_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  0.081  0.763  0.013  1.0
  Li  Li1  1  0.328  0.216  0.753  1.0
  Li  Li2  1  0.672  0.784  0.247  1.0
  Li  Li3  1  0.919  0.237  0.987  1.0
  Cu  Cu4  1  0.114  0.607  0.378  1.0
  Cu  Cu5  1  0.886  0.393  0.622  1.0
  P  P6  1  0.232  0.140  0.391  1.0
  P  P7  1  0.592  0.697  0.885  1.0
  P  P8  1  0.408  0.303  0.115  1.0
  P  P9  1  0.768  0.860  0.609  1.0
  O  O10  1  0.059  0.879  0.330  1.0
  O  O11  1  0.045  0.302  0.415  1.0
  O  O12  1  0.297  0.586  0.873  1.0
  O  O13  1  0.260  0.494  0.176  1.0
  O  O14  1  0.264  0.123  0.950  1.0
  O  O15  1  0.561  0.781  0.466  1.0
  O  O16  1  0.628  0.849  0.766  1.0
  O  O17  1  0.372  0.151  0.234  1.0
  O  O18  1  0.439  0.219  0.534  1.0
  O  O19  1  0.736  0.877  0.050  1.0
  O  O20  1  0.740  0.506  0.824  1.0
  O  O21  1  0.703  0.414  0.127  1.0
  O  O22  1  0.955  0.698  0.585  1.0
  O  O23  1  0.941  0.121  0.670  1.0
[/CIF]
.