The material described by Cr3(P2O7)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(3), one O(7), and two equivalent O(2) atoms to form CrO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Cr(1)O5 trigonal bipyramid. In the second Cr site, Cr(2) is bonded in a square co-planar geometry to two equivalent O(4) and two equivalent O(5) 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(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Cr(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Cr(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cr(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Cr(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Cr(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Cr(2) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cr(1) and one P(2) atom. is represented by the CIF file [CIF]
data_Cr3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.915
_cell_length_b   7.044
_cell_length_c   7.639
_cell_angle_alpha   80.875
_cell_angle_beta   73.585
_cell_angle_gamma   75.277
_symmetry_Int_Tables_number   1
_cell_volume   294.027
_cell_formula_units_Z   1
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
  Cr  Cr0  1  0.758  0.528  0.668  1.0
  Cr  Cr1  1  0.242  0.472  0.332  1.0
  Cr  Cr2  1  0.000  0.000  0.000  1.0
  P  P3  1  0.215  0.698  0.686  1.0
  P  P4  1  0.352  0.325  0.920  1.0
  P  P5  1  0.648  0.675  0.080  1.0
  P  P6  1  0.785  0.302  0.314  1.0
  O  O7  1  0.482  0.678  0.581  1.0
  O  O8  1  0.915  0.384  0.433  1.0
  O  O9  1  0.667  0.681  0.876  1.0
  O  O10  1  0.085  0.616  0.567  1.0
  O  O11  1  0.333  0.319  0.124  1.0
  O  O12  1  0.235  0.178  0.877  1.0
  O  O13  1  0.079  0.896  0.746  1.0
  O  O14  1  0.203  0.547  0.868  1.0
  O  O15  1  0.921  0.104  0.254  1.0
  O  O16  1  0.518  0.322  0.419  1.0
  O  O17  1  0.765  0.822  0.123  1.0
  O  O18  1  0.615  0.312  0.802  1.0
  O  O19  1  0.797  0.453  0.132  1.0
  O  O20  1  0.385  0.688  0.198  1.0
[/CIF]
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The material described by Cr3(P2O7)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(3), one O(7), and two equivalent O(2) atoms to form CrO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Cr(1)O5 trigonal bipyramid. In the second Cr site, Cr(2) is bonded in a square co-planar geometry to two equivalent O(4) and two equivalent O(5) 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(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Cr(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Cr(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cr(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Cr(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Cr(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Cr(2) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cr(1) and one P(2) atom. is represented by the CIF file [CIF]
data_Cr3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.915
_cell_length_b   7.044
_cell_length_c   7.639
_cell_angle_alpha   80.875
_cell_angle_beta   73.585
_cell_angle_gamma   75.277
_symmetry_Int_Tables_number   1
_cell_volume   294.027
_cell_formula_units_Z   1
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
  Cr  Cr0  1  0.758  0.528  0.668  1.0
  Cr  Cr1  1  0.242  0.472  0.332  1.0
  Cr  Cr2  1  0.000  0.000  0.000  1.0
  P  P3  1  0.215  0.698  0.686  1.0
  P  P4  1  0.352  0.325  0.920  1.0
  P  P5  1  0.648  0.675  0.080  1.0
  P  P6  1  0.785  0.302  0.314  1.0
  O  O7  1  0.482  0.678  0.581  1.0
  O  O8  1  0.915  0.384  0.433  1.0
  O  O9  1  0.667  0.681  0.876  1.0
  O  O10  1  0.085  0.616  0.567  1.0
  O  O11  1  0.333  0.319  0.124  1.0
  O  O12  1  0.235  0.178  0.877  1.0
  O  O13  1  0.079  0.896  0.746  1.0
  O  O14  1  0.203  0.547  0.868  1.0
  O  O15  1  0.921  0.104  0.254  1.0
  O  O16  1  0.518  0.322  0.419  1.0
  O  O17  1  0.765  0.822  0.123  1.0
  O  O18  1  0.615  0.312  0.802  1.0
  O  O19  1  0.797  0.453  0.132  1.0
  O  O20  1  0.385  0.688  0.198  1.0
[/CIF]
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