The crystal structure described by Cr5(PO4)4 crystallizes in the triclinic P-1 space group. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form distorted 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(2)O6 octahedra. In the second Cr site, Cr(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form CrO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one P(1)O4 tetrahedra, and edges with two equivalent Cr(3)O5 trigonal bipyramids. In the third Cr site, Cr(3) is bonded to one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form distorted CrO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and edges with two equivalent Cr(2)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, corners with three equivalent Cr(3)O5 trigonal bipyramids, and  an edgeedge with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-59°. In the second P site, P(2) 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 Cr(1)O6 octahedra, corners with three equivalent Cr(2)O6 octahedra, and corners with two equivalent Cr(3)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 44-49°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Cr(1), one Cr(2), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cr(2), one Cr(3), and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Cr(2), one Cr(3), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Cr(2), one Cr(3), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Cr(2), one Cr(3), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted linear geometry to one Cr(3) and one P(1) atom. is represented by the CIF file [CIF]
data_Cr5(PO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.196
_cell_length_b   8.088
_cell_length_c   8.364
_cell_angle_alpha   113.644
_cell_angle_beta   91.667
_cell_angle_gamma   99.130
_symmetry_Int_Tables_number   1
_cell_volume   316.274
_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  0.000  0.000  0.000  1.0
  Cr  Cr1  1  0.116  0.249  0.765  1.0
  Cr  Cr2  1  0.884  0.751  0.235  1.0
  Cr  Cr3  1  0.645  0.416  0.665  1.0
  Cr  Cr4  1  0.355  0.584  0.335  1.0
  O  O5  1  0.345  0.237  0.956  1.0
  O  O6  1  0.655  0.763  0.044  1.0
  O  O7  1  0.801  0.340  0.881  1.0
  O  O8  1  0.199  0.660  0.119  1.0
  O  O9  1  0.337  0.171  0.559  1.0
  O  O10  1  0.663  0.829  0.441  1.0
  O  O11  1  0.048  0.012  0.266  1.0
  O  O12  1  0.952  0.988  0.734  1.0
  O  O13  1  0.918  0.255  0.550  1.0
  O  O14  1  0.082  0.745  0.450  1.0
  O  O15  1  0.751  0.178  0.087  1.0
  O  O16  1  0.249  0.822  0.913  1.0
  O  O17  1  0.338  0.500  0.816  1.0
  O  O18  1  0.662  0.500  0.184  1.0
  O  O19  1  0.260  0.344  0.367  1.0
  O  O20  1  0.740  0.656  0.633  1.0
  P  P21  1  0.141  0.198  0.427  1.0
  P  P22  1  0.859  0.802  0.573  1.0
  P  P23  1  0.641  0.306  0.024  1.0
  P  P24  1  0.359  0.694  0.976  1.0
[/CIF]
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The crystal structure described by Cr5(PO4)4 crystallizes in the triclinic P-1 space group. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form distorted 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(2)O6 octahedra. In the second Cr site, Cr(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form CrO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one P(1)O4 tetrahedra, and edges with two equivalent Cr(3)O5 trigonal bipyramids. In the third Cr site, Cr(3) is bonded to one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form distorted CrO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and edges with two equivalent Cr(2)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, corners with three equivalent Cr(3)O5 trigonal bipyramids, and  an edgeedge with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-59°. In the second P site, P(2) 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 Cr(1)O6 octahedra, corners with three equivalent Cr(2)O6 octahedra, and corners with two equivalent Cr(3)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 44-49°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Cr(1), one Cr(2), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cr(2), one Cr(3), and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Cr(2), one Cr(3), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Cr(2), one Cr(3), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Cr(2), one Cr(3), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted linear geometry to one Cr(3) and one P(1) atom. is represented by the CIF file [CIF]
data_Cr5(PO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.196
_cell_length_b   8.088
_cell_length_c   8.364
_cell_angle_alpha   113.644
_cell_angle_beta   91.667
_cell_angle_gamma   99.130
_symmetry_Int_Tables_number   1
_cell_volume   316.274
_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  0.000  0.000  0.000  1.0
  Cr  Cr1  1  0.116  0.249  0.765  1.0
  Cr  Cr2  1  0.884  0.751  0.235  1.0
  Cr  Cr3  1  0.645  0.416  0.665  1.0
  Cr  Cr4  1  0.355  0.584  0.335  1.0
  O  O5  1  0.345  0.237  0.956  1.0
  O  O6  1  0.655  0.763  0.044  1.0
  O  O7  1  0.801  0.340  0.881  1.0
  O  O8  1  0.199  0.660  0.119  1.0
  O  O9  1  0.337  0.171  0.559  1.0
  O  O10  1  0.663  0.829  0.441  1.0
  O  O11  1  0.048  0.012  0.266  1.0
  O  O12  1  0.952  0.988  0.734  1.0
  O  O13  1  0.918  0.255  0.550  1.0
  O  O14  1  0.082  0.745  0.450  1.0
  O  O15  1  0.751  0.178  0.087  1.0
  O  O16  1  0.249  0.822  0.913  1.0
  O  O17  1  0.338  0.500  0.816  1.0
  O  O18  1  0.662  0.500  0.184  1.0
  O  O19  1  0.260  0.344  0.367  1.0
  O  O20  1  0.740  0.656  0.633  1.0
  P  P21  1  0.141  0.198  0.427  1.0
  P  P22  1  0.859  0.802  0.573  1.0
  P  P23  1  0.641  0.306  0.024  1.0
  P  P24  1  0.359  0.694  0.976  1.0
[/CIF]
.