The compound described by CaCr2(PO4)2 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and two equivalent O(8) atoms. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(6), and one O(7) atom. In the second Cr site, Cr(2) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. In the third Cr site, Cr(3) is bonded to two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms to form distorted CrO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with four equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. In the second P site, P(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-50°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(2), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one P(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ca(1), one Cr(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), one Cr(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ca(1), one Cr(3), and one P(2) atom. In the sixth O site, O(6) is bonded to one Ca(1), one Cr(1), one Cr(3), and one P(2) atom to form distorted corner-sharing OCaCr2P tetrahedra. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(3), and one P(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaCr2(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.183
_cell_length_b   9.183
_cell_length_c   17.049
_cell_angle_alpha   62.246
_cell_angle_beta   62.246
_cell_angle_gamma   32.198
_symmetry_Int_Tables_number   1
_cell_volume   670.128
_cell_formula_units_Z   4
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  0.470  0.831  0.862  1.0
  Ca  Ca1  1  0.169  0.530  0.638  1.0
  Ca  Ca2  1  0.831  0.470  0.362  1.0
  Ca  Ca3  1  0.530  0.169  0.138  1.0
  Cr  Cr4  1  0.159  0.645  0.963  1.0
  Cr  Cr5  1  0.355  0.841  0.537  1.0
  Cr  Cr6  1  0.841  0.355  0.037  1.0
  Cr  Cr7  1  0.500  0.000  0.000  1.0
  Cr  Cr8  1  0.645  0.159  0.463  1.0
  Cr  Cr9  1  0.692  0.308  0.250  1.0
  Cr  Cr10  1  0.308  0.692  0.750  1.0
  Cr  Cr11  1  0.000  0.500  0.500  1.0
  P  P12  1  0.052  0.514  0.867  1.0
  P  P13  1  0.769  0.199  0.608  1.0
  P  P14  1  0.948  0.486  0.133  1.0
  P  P15  1  0.199  0.769  0.108  1.0
  P  P16  1  0.514  0.052  0.367  1.0
  P  P17  1  0.486  0.948  0.633  1.0
  P  P18  1  0.231  0.801  0.392  1.0
  P  P19  1  0.801  0.231  0.892  1.0
  O  O20  1  0.698  0.805  0.105  1.0
  O  O21  1  0.825  0.342  0.926  1.0
  O  O22  1  0.805  0.698  0.605  1.0
  O  O23  1  0.806  0.348  0.532  1.0
  O  O24  1  0.193  0.361  0.052  1.0
  O  O25  1  0.558  0.351  0.689  1.0
  O  O26  1  0.652  0.194  0.968  1.0
  O  O27  1  0.893  0.066  0.132  1.0
  O  O28  1  0.194  0.652  0.468  1.0
  O  O29  1  0.658  0.175  0.574  1.0
  O  O30  1  0.873  0.375  0.143  1.0
  O  O31  1  0.607  0.952  0.285  1.0
  O  O32  1  0.175  0.658  0.074  1.0
  O  O33  1  0.066  0.893  0.632  1.0
  O  O34  1  0.302  0.195  0.895  1.0
  O  O35  1  0.127  0.625  0.857  1.0
  O  O36  1  0.952  0.607  0.785  1.0
  O  O37  1  0.348  0.806  0.032  1.0
  O  O38  1  0.375  0.873  0.643  1.0
  O  O39  1  0.393  0.048  0.715  1.0
  O  O40  1  0.934  0.107  0.368  1.0
  O  O41  1  0.361  0.193  0.552  1.0
  O  O42  1  0.107  0.934  0.868  1.0
  O  O43  1  0.351  0.558  0.189  1.0
  O  O44  1  0.342  0.825  0.426  1.0
  O  O45  1  0.195  0.302  0.395  1.0
  O  O46  1  0.048  0.393  0.215  1.0
  O  O47  1  0.639  0.807  0.448  1.0
  O  O48  1  0.807  0.639  0.948  1.0
  O  O49  1  0.649  0.442  0.811  1.0
  O  O50  1  0.442  0.649  0.311  1.0
  O  O51  1  0.625  0.127  0.357  1.0
[/CIF]
.
The compound described by CaCr2(PO4)2 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and two equivalent O(8) atoms. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(6), and one O(7) atom. In the second Cr site, Cr(2) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. In the third Cr site, Cr(3) is bonded to two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms to form distorted CrO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with four equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. In the second P site, P(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-50°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(2), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one P(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ca(1), one Cr(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), one Cr(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ca(1), one Cr(3), and one P(2) atom. In the sixth O site, O(6) is bonded to one Ca(1), one Cr(1), one Cr(3), and one P(2) atom to form distorted corner-sharing OCaCr2P tetrahedra. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(3), and one P(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaCr2(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.183
_cell_length_b   9.183
_cell_length_c   17.049
_cell_angle_alpha   62.246
_cell_angle_beta   62.246
_cell_angle_gamma   32.198
_symmetry_Int_Tables_number   1
_cell_volume   670.128
_cell_formula_units_Z   4
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  0.470  0.831  0.862  1.0
  Ca  Ca1  1  0.169  0.530  0.638  1.0
  Ca  Ca2  1  0.831  0.470  0.362  1.0
  Ca  Ca3  1  0.530  0.169  0.138  1.0
  Cr  Cr4  1  0.159  0.645  0.963  1.0
  Cr  Cr5  1  0.355  0.841  0.537  1.0
  Cr  Cr6  1  0.841  0.355  0.037  1.0
  Cr  Cr7  1  0.500  0.000  0.000  1.0
  Cr  Cr8  1  0.645  0.159  0.463  1.0
  Cr  Cr9  1  0.692  0.308  0.250  1.0
  Cr  Cr10  1  0.308  0.692  0.750  1.0
  Cr  Cr11  1  0.000  0.500  0.500  1.0
  P  P12  1  0.052  0.514  0.867  1.0
  P  P13  1  0.769  0.199  0.608  1.0
  P  P14  1  0.948  0.486  0.133  1.0
  P  P15  1  0.199  0.769  0.108  1.0
  P  P16  1  0.514  0.052  0.367  1.0
  P  P17  1  0.486  0.948  0.633  1.0
  P  P18  1  0.231  0.801  0.392  1.0
  P  P19  1  0.801  0.231  0.892  1.0
  O  O20  1  0.698  0.805  0.105  1.0
  O  O21  1  0.825  0.342  0.926  1.0
  O  O22  1  0.805  0.698  0.605  1.0
  O  O23  1  0.806  0.348  0.532  1.0
  O  O24  1  0.193  0.361  0.052  1.0
  O  O25  1  0.558  0.351  0.689  1.0
  O  O26  1  0.652  0.194  0.968  1.0
  O  O27  1  0.893  0.066  0.132  1.0
  O  O28  1  0.194  0.652  0.468  1.0
  O  O29  1  0.658  0.175  0.574  1.0
  O  O30  1  0.873  0.375  0.143  1.0
  O  O31  1  0.607  0.952  0.285  1.0
  O  O32  1  0.175  0.658  0.074  1.0
  O  O33  1  0.066  0.893  0.632  1.0
  O  O34  1  0.302  0.195  0.895  1.0
  O  O35  1  0.127  0.625  0.857  1.0
  O  O36  1  0.952  0.607  0.785  1.0
  O  O37  1  0.348  0.806  0.032  1.0
  O  O38  1  0.375  0.873  0.643  1.0
  O  O39  1  0.393  0.048  0.715  1.0
  O  O40  1  0.934  0.107  0.368  1.0
  O  O41  1  0.361  0.193  0.552  1.0
  O  O42  1  0.107  0.934  0.868  1.0
  O  O43  1  0.351  0.558  0.189  1.0
  O  O44  1  0.342  0.825  0.426  1.0
  O  O45  1  0.195  0.302  0.395  1.0
  O  O46  1  0.048  0.393  0.215  1.0
  O  O47  1  0.639  0.807  0.448  1.0
  O  O48  1  0.807  0.639  0.948  1.0
  O  O49  1  0.649  0.442  0.811  1.0
  O  O50  1  0.442  0.649  0.311  1.0
  O  O51  1  0.625  0.127  0.357  1.0
[/CIF]
.