The structure described by Ca3Cr3(AsO4)4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(4), one O(5), one O(7), one O(8), and two equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(8) atoms to form CaO6 octahedra that share corners with two equivalent As(2)O4 tetrahedra, corners with four equivalent As(1)O4 tetrahedra, and edges with two equivalent Cr(1)O5 trigonal bipyramids. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), one O(4), one O(7), and one O(8) atom to form CrO5 trigonal bipyramids that share corners with two equivalent As(2)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra, and  an edgeedge with one Ca(2)O6 octahedra. In the second Cr site, Cr(2) is bonded in a square co-planar geometry to two equivalent O(5) and two equivalent O(7) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share corners with two equivalent Ca(2)O6 octahedra and corners with three equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 43-61°. In the second As site, As(2) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one Ca(2)O6 octahedra and corners with two equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 53°. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), one Cr(2), and one As(2) atom. In the second O site, O(8) is bonded to one Ca(1), one Ca(2), one Cr(1), and one As(1) atom to form distorted corner-sharing OCa2CrAs tetrahedra. In the third O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Cr(1), and one As(1) atom. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(2), one Cr(1), and one As(2) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one As(2) atom. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(1), and one As(1) atom. In the seventh O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(2), and one As(2) atom. In the eighth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Ca(2) and one As(1) atom. is represented by the CIF card [CIF]
data_Ca3Cr3(AsO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.229
_cell_length_b   9.344
_cell_length_c   17.357
_cell_angle_alpha   63.209
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   756.989
_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
  Ca  Ca0  1  0.533  0.304  0.234  1.0
  Ca  Ca1  1  0.033  0.696  0.266  1.0
  Ca  Ca2  1  0.467  0.696  0.766  1.0
  Ca  Ca3  1  0.967  0.304  0.734  1.0
  Ca  Ca4  1  0.500  0.000  0.500  1.0
  Ca  Ca5  1  0.000  0.000  0.000  1.0
  Cr  Cr6  1  0.477  0.207  0.619  1.0
  Cr  Cr7  1  0.523  0.793  0.381  1.0
  Cr  Cr8  1  0.977  0.793  0.881  1.0
  Cr  Cr9  1  0.023  0.207  0.119  1.0
  Cr  Cr10  1  0.000  0.500  0.500  1.0
  Cr  Cr11  1  0.500  0.500  0.000  1.0
  As  As12  1  0.007  0.041  0.342  1.0
  As  As13  1  0.492  0.435  0.403  1.0
  As  As14  1  0.992  0.565  0.097  1.0
  As  As15  1  0.008  0.435  0.903  1.0
  As  As16  1  0.993  0.959  0.658  1.0
  As  As17  1  0.508  0.565  0.597  1.0
  As  As18  1  0.493  0.041  0.842  1.0
  As  As19  1  0.507  0.959  0.158  1.0
  O  O20  1  0.443  0.811  0.263  1.0
  O  O21  1  0.941  0.746  0.008  1.0
  O  O22  1  0.390  0.437  0.311  1.0
  O  O23  1  0.413  0.143  0.151  1.0
  O  O24  1  0.610  0.563  0.689  1.0
  O  O25  1  0.057  0.811  0.763  1.0
  O  O26  1  0.890  0.563  0.189  1.0
  O  O27  1  0.697  0.505  0.896  1.0
  O  O28  1  0.666  0.099  0.905  1.0
  O  O29  1  0.557  0.189  0.737  1.0
  O  O30  1  0.087  0.143  0.651  1.0
  O  O31  1  0.303  0.495  0.104  1.0
  O  O32  1  0.305  0.577  0.419  1.0
  O  O33  1  0.334  0.901  0.095  1.0
  O  O34  1  0.666  0.961  0.642  1.0
  O  O35  1  0.166  0.039  0.858  1.0
  O  O36  1  0.805  0.423  0.081  1.0
  O  O37  1  0.110  0.437  0.811  1.0
  O  O38  1  0.166  0.901  0.595  1.0
  O  O39  1  0.197  0.495  0.604  1.0
  O  O40  1  0.834  0.961  0.142  1.0
  O  O41  1  0.334  0.039  0.358  1.0
  O  O42  1  0.059  0.254  0.992  1.0
  O  O43  1  0.441  0.254  0.492  1.0
  O  O44  1  0.695  0.423  0.581  1.0
  O  O45  1  0.943  0.189  0.237  1.0
  O  O46  1  0.587  0.857  0.849  1.0
  O  O47  1  0.834  0.099  0.405  1.0
  O  O48  1  0.559  0.746  0.508  1.0
  O  O49  1  0.803  0.505  0.396  1.0
  O  O50  1  0.195  0.577  0.919  1.0
  O  O51  1  0.913  0.857  0.349  1.0
[/CIF]
.
The structure described by Ca3Cr3(AsO4)4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(4), one O(5), one O(7), one O(8), and two equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(8) atoms to form CaO6 octahedra that share corners with two equivalent As(2)O4 tetrahedra, corners with four equivalent As(1)O4 tetrahedra, and edges with two equivalent Cr(1)O5 trigonal bipyramids. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), one O(4), one O(7), and one O(8) atom to form CrO5 trigonal bipyramids that share corners with two equivalent As(2)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra, and  an edgeedge with one Ca(2)O6 octahedra. In the second Cr site, Cr(2) is bonded in a square co-planar geometry to two equivalent O(5) and two equivalent O(7) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share corners with two equivalent Ca(2)O6 octahedra and corners with three equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 43-61°. In the second As site, As(2) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one Ca(2)O6 octahedra and corners with two equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 53°. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), one Cr(2), and one As(2) atom. In the second O site, O(8) is bonded to one Ca(1), one Ca(2), one Cr(1), and one As(1) atom to form distorted corner-sharing OCa2CrAs tetrahedra. In the third O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Cr(1), and one As(1) atom. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(2), one Cr(1), and one As(2) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one As(2) atom. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(1), and one As(1) atom. In the seventh O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(2), and one As(2) atom. In the eighth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Ca(2) and one As(1) atom. is represented by the CIF card [CIF]
data_Ca3Cr3(AsO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.229
_cell_length_b   9.344
_cell_length_c   17.357
_cell_angle_alpha   63.209
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   756.989
_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
  Ca  Ca0  1  0.533  0.304  0.234  1.0
  Ca  Ca1  1  0.033  0.696  0.266  1.0
  Ca  Ca2  1  0.467  0.696  0.766  1.0
  Ca  Ca3  1  0.967  0.304  0.734  1.0
  Ca  Ca4  1  0.500  0.000  0.500  1.0
  Ca  Ca5  1  0.000  0.000  0.000  1.0
  Cr  Cr6  1  0.477  0.207  0.619  1.0
  Cr  Cr7  1  0.523  0.793  0.381  1.0
  Cr  Cr8  1  0.977  0.793  0.881  1.0
  Cr  Cr9  1  0.023  0.207  0.119  1.0
  Cr  Cr10  1  0.000  0.500  0.500  1.0
  Cr  Cr11  1  0.500  0.500  0.000  1.0
  As  As12  1  0.007  0.041  0.342  1.0
  As  As13  1  0.492  0.435  0.403  1.0
  As  As14  1  0.992  0.565  0.097  1.0
  As  As15  1  0.008  0.435  0.903  1.0
  As  As16  1  0.993  0.959  0.658  1.0
  As  As17  1  0.508  0.565  0.597  1.0
  As  As18  1  0.493  0.041  0.842  1.0
  As  As19  1  0.507  0.959  0.158  1.0
  O  O20  1  0.443  0.811  0.263  1.0
  O  O21  1  0.941  0.746  0.008  1.0
  O  O22  1  0.390  0.437  0.311  1.0
  O  O23  1  0.413  0.143  0.151  1.0
  O  O24  1  0.610  0.563  0.689  1.0
  O  O25  1  0.057  0.811  0.763  1.0
  O  O26  1  0.890  0.563  0.189  1.0
  O  O27  1  0.697  0.505  0.896  1.0
  O  O28  1  0.666  0.099  0.905  1.0
  O  O29  1  0.557  0.189  0.737  1.0
  O  O30  1  0.087  0.143  0.651  1.0
  O  O31  1  0.303  0.495  0.104  1.0
  O  O32  1  0.305  0.577  0.419  1.0
  O  O33  1  0.334  0.901  0.095  1.0
  O  O34  1  0.666  0.961  0.642  1.0
  O  O35  1  0.166  0.039  0.858  1.0
  O  O36  1  0.805  0.423  0.081  1.0
  O  O37  1  0.110  0.437  0.811  1.0
  O  O38  1  0.166  0.901  0.595  1.0
  O  O39  1  0.197  0.495  0.604  1.0
  O  O40  1  0.834  0.961  0.142  1.0
  O  O41  1  0.334  0.039  0.358  1.0
  O  O42  1  0.059  0.254  0.992  1.0
  O  O43  1  0.441  0.254  0.492  1.0
  O  O44  1  0.695  0.423  0.581  1.0
  O  O45  1  0.943  0.189  0.237  1.0
  O  O46  1  0.587  0.857  0.849  1.0
  O  O47  1  0.834  0.099  0.405  1.0
  O  O48  1  0.559  0.746  0.508  1.0
  O  O49  1  0.803  0.505  0.396  1.0
  O  O50  1  0.195  0.577  0.919  1.0
  O  O51  1  0.913  0.857  0.349  1.0
[/CIF]
.