The crystal structure described by CaCr4(PO4)4 crystallizes in the triclinic P1 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(11), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(15), one O(16), one O(3), and one O(5) atom to form distorted CrO5 trigonal bipyramids that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-77°. In the second Cr site, Cr(2) is bonded to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form distorted CrO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one Cr(1)O5 trigonal bipyramid, and  an edgeedge with one P(2)O4 tetrahedra. In the third Cr site, Cr(3) is bonded to one O(10), one O(11), one O(12), one O(13), one O(15), and one O(9) atom to form distorted CrO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one Cr(1)O5 trigonal bipyramid, and  an edgeedge with one P(3)O4 tetrahedra. In the fourth Cr site, Cr(4) is bonded in a 6-coordinate geometry to one O(1), one O(12), one O(13), one O(14), one O(16), and one O(2) atom. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(13), one O(2), and one O(3) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra, and corners with two equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 44-49°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra,  a cornercorner with one Cr(1)O5 trigonal bipyramid, and  an edgeedge with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-50°. In the third P site, P(3) is bonded to one O(10), one O(11), one O(12), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra, and  an edgeedge with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-46°. In the fourth P site, P(4) is bonded to one O(14), one O(15), one O(16), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra, and corners with two equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 47-52°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Cr(1), one Cr(4), and one P(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Cr(2), one Cr(4), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Ca(1), one Cr(2), and one P(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Cr(1), one Cr(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Ca(1), one Cr(2), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(2), and one P(3) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Cr(3) and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Cr(3) and one P(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(3), and one P(3) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Cr(3), one Cr(4), and one P(3) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to one Cr(3), one Cr(4), and one P(1) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Cr(4) and one P(4) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(3), and one P(4) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal non-coplanar geometry to one Cr(1), one Cr(4), and one P(4) atom. is represented by the CIF file [CIF]
data_CaCr4(PO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.423
_cell_length_b   5.650
_cell_length_c   6.461
_cell_angle_alpha   100.966
_cell_angle_beta   104.003
_cell_angle_gamma   81.243
_symmetry_Int_Tables_number   1
_cell_volume   325.609
_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
  Ca  Ca0  1  0.322  0.941  0.065  1.0
  Cr  Cr1  1  0.072  0.308  0.340  1.0
  Cr  Cr2  1  0.290  0.863  0.550  1.0
  Cr  Cr3  1  0.708  0.134  0.441  1.0
  Cr  Cr4  1  0.915  0.692  0.666  1.0
  P  P5  1  0.036  0.193  0.787  1.0
  P  P6  1  0.407  0.302  0.649  1.0
  P  P7  1  0.595  0.697  0.354  1.0
  P  P8  1  0.963  0.807  0.213  1.0
  O  O9  1  0.071  0.385  0.668  1.0
  O  O10  1  0.126  0.941  0.715  1.0
  O  O11  1  0.103  0.245  0.032  1.0
  O  O12  1  0.136  0.817  0.267  1.0
  O  O13  1  0.298  0.180  0.433  1.0
  O  O14  1  0.399  0.117  0.799  1.0
  O  O15  1  0.345  0.568  0.722  1.0
  O  O16  1  0.431  0.707  0.369  1.0
  O  O17  1  0.558  0.293  0.606  1.0
  O  O18  1  0.657  0.435  0.290  1.0
  O  O19  1  0.586  0.886  0.199  1.0
  O  O20  1  0.696  0.826  0.563  1.0
  O  O21  1  0.870  0.173  0.727  1.0
  O  O22  1  0.910  0.726  0.975  1.0
  O  O23  1  0.887  0.059  0.298  1.0
  O  O24  1  0.932  0.624  0.345  1.0
[/CIF]
.
The crystal structure described by CaCr4(PO4)4 crystallizes in the triclinic P1 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(11), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(15), one O(16), one O(3), and one O(5) atom to form distorted CrO5 trigonal bipyramids that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-77°. In the second Cr site, Cr(2) is bonded to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form distorted CrO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one Cr(1)O5 trigonal bipyramid, and  an edgeedge with one P(2)O4 tetrahedra. In the third Cr site, Cr(3) is bonded to one O(10), one O(11), one O(12), one O(13), one O(15), and one O(9) atom to form distorted CrO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one Cr(1)O5 trigonal bipyramid, and  an edgeedge with one P(3)O4 tetrahedra. In the fourth Cr site, Cr(4) is bonded in a 6-coordinate geometry to one O(1), one O(12), one O(13), one O(14), one O(16), and one O(2) atom. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(13), one O(2), and one O(3) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra, and corners with two equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 44-49°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra,  a cornercorner with one Cr(1)O5 trigonal bipyramid, and  an edgeedge with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-50°. In the third P site, P(3) is bonded to one O(10), one O(11), one O(12), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra, and  an edgeedge with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-46°. In the fourth P site, P(4) is bonded to one O(14), one O(15), one O(16), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra, and corners with two equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 47-52°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Cr(1), one Cr(4), and one P(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Cr(2), one Cr(4), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Ca(1), one Cr(2), and one P(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Cr(1), one Cr(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Ca(1), one Cr(2), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(2), and one P(3) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Cr(3) and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Cr(3) and one P(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(3), and one P(3) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Cr(3), one Cr(4), and one P(3) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to one Cr(3), one Cr(4), and one P(1) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Cr(4) and one P(4) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(3), and one P(4) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal non-coplanar geometry to one Cr(1), one Cr(4), and one P(4) atom. is represented by the CIF file [CIF]
data_CaCr4(PO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.423
_cell_length_b   5.650
_cell_length_c   6.461
_cell_angle_alpha   100.966
_cell_angle_beta   104.003
_cell_angle_gamma   81.243
_symmetry_Int_Tables_number   1
_cell_volume   325.609
_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
  Ca  Ca0  1  0.322  0.941  0.065  1.0
  Cr  Cr1  1  0.072  0.308  0.340  1.0
  Cr  Cr2  1  0.290  0.863  0.550  1.0
  Cr  Cr3  1  0.708  0.134  0.441  1.0
  Cr  Cr4  1  0.915  0.692  0.666  1.0
  P  P5  1  0.036  0.193  0.787  1.0
  P  P6  1  0.407  0.302  0.649  1.0
  P  P7  1  0.595  0.697  0.354  1.0
  P  P8  1  0.963  0.807  0.213  1.0
  O  O9  1  0.071  0.385  0.668  1.0
  O  O10  1  0.126  0.941  0.715  1.0
  O  O11  1  0.103  0.245  0.032  1.0
  O  O12  1  0.136  0.817  0.267  1.0
  O  O13  1  0.298  0.180  0.433  1.0
  O  O14  1  0.399  0.117  0.799  1.0
  O  O15  1  0.345  0.568  0.722  1.0
  O  O16  1  0.431  0.707  0.369  1.0
  O  O17  1  0.558  0.293  0.606  1.0
  O  O18  1  0.657  0.435  0.290  1.0
  O  O19  1  0.586  0.886  0.199  1.0
  O  O20  1  0.696  0.826  0.563  1.0
  O  O21  1  0.870  0.173  0.727  1.0
  O  O22  1  0.910  0.726  0.975  1.0
  O  O23  1  0.887  0.059  0.298  1.0
  O  O24  1  0.932  0.624  0.345  1.0
[/CIF]
.