The structure described by Li2Cr3(P2O7)2 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(4), one O(6), and one O(7) atom. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form distorted CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Cr(1)O6 octahedra, and  an edgeedge with one Cr(2)O6 octahedra. In the second Cr site, Cr(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(7) atoms to form CrO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and edges with two equivalent Cr(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-58°. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Cr(2)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-62°. There are seven inequivalent O sites. In the first O site, O(7) is bonded to one Li(1), one Cr(1), one Cr(2), and one P(2) atom to form distorted corner-sharing OLiCr2P trigonal pyramids. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one Cr(2), and one P(2) atom. In the third O site, O(2) is bonded in a 4-coordinate geometry to one Li(1), one Cr(1), one Cr(2), and one P(1) atom. In the fourth O site, O(3) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), one Cr(1), and one P(1) atom. In the sixth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Cr(1) and one P(2) atom. In the seventh O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(1), one Cr(1), and one P(1) atom. is represented by the CIF file [CIF]
data_Li2Cr3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.114
_cell_length_b   7.398
_cell_length_c   9.625
_cell_angle_alpha   71.491
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   547.894
_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  0.581  0.296  0.143  1.0
  Li  Li1  1  0.081  0.704  0.357  1.0
  Li  Li2  1  0.919  0.296  0.643  1.0
  Li  Li3  1  0.419  0.704  0.857  1.0
  Cr  Cr4  1  0.373  0.805  0.519  1.0
  Cr  Cr5  1  0.873  0.195  0.981  1.0
  Cr  Cr6  1  0.127  0.805  0.019  1.0
  Cr  Cr7  1  0.000  0.000  0.500  1.0
  Cr  Cr8  1  0.627  0.195  0.481  1.0
  Cr  Cr9  1  0.500  0.000  0.000  1.0
  P  P10  1  0.457  0.597  0.283  1.0
  P  P11  1  0.710  0.891  0.302  1.0
  P  P12  1  0.043  0.597  0.783  1.0
  P  P13  1  0.543  0.403  0.717  1.0
  P  P14  1  0.790  0.891  0.802  1.0
  P  P15  1  0.957  0.403  0.217  1.0
  P  P16  1  0.290  0.109  0.698  1.0
  P  P17  1  0.210  0.109  0.198  1.0
  O  O18  1  0.121  0.147  0.625  1.0
  O  O19  1  0.903  0.298  0.374  1.0
  O  O20  1  0.365  0.313  0.688  1.0
  O  O21  1  0.635  0.687  0.312  1.0
  O  O22  1  0.997  0.389  0.806  1.0
  O  O23  1  0.497  0.611  0.694  1.0
  O  O24  1  0.865  0.687  0.812  1.0
  O  O25  1  0.407  0.012  0.619  1.0
  O  O26  1  0.097  0.702  0.626  1.0
  O  O27  1  0.907  0.988  0.881  1.0
  O  O28  1  0.665  0.376  0.603  1.0
  O  O29  1  0.003  0.611  0.194  1.0
  O  O30  1  0.597  0.298  0.874  1.0
  O  O31  1  0.335  0.624  0.397  1.0
  O  O32  1  0.787  0.006  0.636  1.0
  O  O33  1  0.593  0.988  0.381  1.0
  O  O34  1  0.403  0.702  0.126  1.0
  O  O35  1  0.713  0.006  0.136  1.0
  O  O36  1  0.503  0.389  0.306  1.0
  O  O37  1  0.879  0.853  0.375  1.0
  O  O38  1  0.213  0.994  0.364  1.0
  O  O39  1  0.621  0.853  0.875  1.0
  O  O40  1  0.379  0.147  0.125  1.0
  O  O41  1  0.835  0.376  0.103  1.0
  O  O42  1  0.093  0.012  0.119  1.0
  O  O43  1  0.135  0.313  0.188  1.0
  O  O44  1  0.165  0.624  0.897  1.0
  O  O45  1  0.287  0.994  0.864  1.0
[/CIF]
.
The structure described by Li2Cr3(P2O7)2 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(4), one O(6), and one O(7) atom. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form distorted CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Cr(1)O6 octahedra, and  an edgeedge with one Cr(2)O6 octahedra. In the second Cr site, Cr(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(7) atoms to form CrO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and edges with two equivalent Cr(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-58°. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Cr(2)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-62°. There are seven inequivalent O sites. In the first O site, O(7) is bonded to one Li(1), one Cr(1), one Cr(2), and one P(2) atom to form distorted corner-sharing OLiCr2P trigonal pyramids. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one Cr(2), and one P(2) atom. In the third O site, O(2) is bonded in a 4-coordinate geometry to one Li(1), one Cr(1), one Cr(2), and one P(1) atom. In the fourth O site, O(3) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), one Cr(1), and one P(1) atom. In the sixth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Cr(1) and one P(2) atom. In the seventh O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(1), one Cr(1), and one P(1) atom. is represented by the CIF file [CIF]
data_Li2Cr3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.114
_cell_length_b   7.398
_cell_length_c   9.625
_cell_angle_alpha   71.491
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   547.894
_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  0.581  0.296  0.143  1.0
  Li  Li1  1  0.081  0.704  0.357  1.0
  Li  Li2  1  0.919  0.296  0.643  1.0
  Li  Li3  1  0.419  0.704  0.857  1.0
  Cr  Cr4  1  0.373  0.805  0.519  1.0
  Cr  Cr5  1  0.873  0.195  0.981  1.0
  Cr  Cr6  1  0.127  0.805  0.019  1.0
  Cr  Cr7  1  0.000  0.000  0.500  1.0
  Cr  Cr8  1  0.627  0.195  0.481  1.0
  Cr  Cr9  1  0.500  0.000  0.000  1.0
  P  P10  1  0.457  0.597  0.283  1.0
  P  P11  1  0.710  0.891  0.302  1.0
  P  P12  1  0.043  0.597  0.783  1.0
  P  P13  1  0.543  0.403  0.717  1.0
  P  P14  1  0.790  0.891  0.802  1.0
  P  P15  1  0.957  0.403  0.217  1.0
  P  P16  1  0.290  0.109  0.698  1.0
  P  P17  1  0.210  0.109  0.198  1.0
  O  O18  1  0.121  0.147  0.625  1.0
  O  O19  1  0.903  0.298  0.374  1.0
  O  O20  1  0.365  0.313  0.688  1.0
  O  O21  1  0.635  0.687  0.312  1.0
  O  O22  1  0.997  0.389  0.806  1.0
  O  O23  1  0.497  0.611  0.694  1.0
  O  O24  1  0.865  0.687  0.812  1.0
  O  O25  1  0.407  0.012  0.619  1.0
  O  O26  1  0.097  0.702  0.626  1.0
  O  O27  1  0.907  0.988  0.881  1.0
  O  O28  1  0.665  0.376  0.603  1.0
  O  O29  1  0.003  0.611  0.194  1.0
  O  O30  1  0.597  0.298  0.874  1.0
  O  O31  1  0.335  0.624  0.397  1.0
  O  O32  1  0.787  0.006  0.636  1.0
  O  O33  1  0.593  0.988  0.381  1.0
  O  O34  1  0.403  0.702  0.126  1.0
  O  O35  1  0.713  0.006  0.136  1.0
  O  O36  1  0.503  0.389  0.306  1.0
  O  O37  1  0.879  0.853  0.375  1.0
  O  O38  1  0.213  0.994  0.364  1.0
  O  O39  1  0.621  0.853  0.875  1.0
  O  O40  1  0.379  0.147  0.125  1.0
  O  O41  1  0.835  0.376  0.103  1.0
  O  O42  1  0.093  0.012  0.119  1.0
  O  O43  1  0.135  0.313  0.188  1.0
  O  O44  1  0.165  0.624  0.897  1.0
  O  O45  1  0.287  0.994  0.864  1.0
[/CIF]
.