The material structure described by Cr2Fe3Sb(PO4)6 crystallizes in the trigonal R3 space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(6) atoms. In the second Cr site, Cr(2) is bonded to three equivalent O(4) and three equivalent O(7) atoms to form distorted CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Fe(2)O6 octahedra, and  a faceface with one Fe(3)O6 octahedra. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form distorted FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Cr(2)O6 octahedra. In the third Fe site, Fe(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Cr(2)O6 octahedra. Sb(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form SbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra, and  a cornercorner with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-54°. In the second P site, P(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra, and  a cornercorner with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-53°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cr(1), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Sb(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Cr(2), one Fe(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Cr(1), one Sb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Cr(2), one Fe(3), and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cr2Fe3Sb(PO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.580
_cell_length_b   8.580
_cell_length_c   8.580
_cell_angle_alpha   60.664
_cell_angle_beta   60.664
_cell_angle_gamma   60.664
_symmetry_Int_Tables_number   1
_cell_volume   453.378
_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  0.996  0.996  0.996  1.0
  Cr  Cr1  1  0.502  0.502  0.502  1.0
  Fe  Fe2  1  0.854  0.854  0.854  1.0
  Fe  Fe3  1  0.644  0.644  0.644  1.0
  Fe  Fe4  1  0.355  0.355  0.355  1.0
  Sb  Sb5  1  0.144  0.144  0.144  1.0
  P  P6  1  0.254  0.547  0.951  1.0
  P  P7  1  0.746  0.460  0.049  1.0
  P  P8  1  0.460  0.049  0.746  1.0
  P  P9  1  0.049  0.746  0.460  1.0
  P  P10  1  0.951  0.254  0.547  1.0
  P  P11  1  0.547  0.951  0.254  1.0
  O  O12  1  0.900  0.685  0.485  1.0
  O  O13  1  0.685  0.485  0.900  1.0
  O  O14  1  0.941  0.090  0.739  1.0
  O  O15  1  0.485  0.900  0.685  1.0
  O  O16  1  0.990  0.183  0.389  1.0
  O  O17  1  0.753  0.407  0.556  1.0
  O  O18  1  0.739  0.941  0.090  1.0
  O  O19  1  0.556  0.753  0.407  1.0
  O  O20  1  0.819  0.610  0.009  1.0
  O  O21  1  0.407  0.556  0.753  1.0
  O  O22  1  0.911  0.254  0.069  1.0
  O  O23  1  0.610  0.009  0.819  1.0
  O  O24  1  0.389  0.990  0.183  1.0
  O  O25  1  0.090  0.739  0.941  1.0
  O  O26  1  0.593  0.438  0.253  1.0
  O  O27  1  0.183  0.389  0.990  1.0
  O  O28  1  0.438  0.253  0.593  1.0
  O  O29  1  0.254  0.069  0.911  1.0
  O  O30  1  0.253  0.593  0.438  1.0
  O  O31  1  0.009  0.819  0.610  1.0
  O  O32  1  0.497  0.109  0.320  1.0
  O  O33  1  0.069  0.911  0.254  1.0
  O  O34  1  0.320  0.497  0.109  1.0
  O  O35  1  0.109  0.320  0.497  1.0
[/CIF]
.
The material structure described by Cr2Fe3Sb(PO4)6 crystallizes in the trigonal R3 space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(6) atoms. In the second Cr site, Cr(2) is bonded to three equivalent O(4) and three equivalent O(7) atoms to form distorted CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Fe(2)O6 octahedra, and  a faceface with one Fe(3)O6 octahedra. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form distorted FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Cr(2)O6 octahedra. In the third Fe site, Fe(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Cr(2)O6 octahedra. Sb(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form SbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra, and  a cornercorner with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-54°. In the second P site, P(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra, and  a cornercorner with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-53°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cr(1), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Sb(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Cr(2), one Fe(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Cr(1), one Sb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Cr(2), one Fe(3), and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cr2Fe3Sb(PO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.580
_cell_length_b   8.580
_cell_length_c   8.580
_cell_angle_alpha   60.664
_cell_angle_beta   60.664
_cell_angle_gamma   60.664
_symmetry_Int_Tables_number   1
_cell_volume   453.378
_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  0.996  0.996  0.996  1.0
  Cr  Cr1  1  0.502  0.502  0.502  1.0
  Fe  Fe2  1  0.854  0.854  0.854  1.0
  Fe  Fe3  1  0.644  0.644  0.644  1.0
  Fe  Fe4  1  0.355  0.355  0.355  1.0
  Sb  Sb5  1  0.144  0.144  0.144  1.0
  P  P6  1  0.254  0.547  0.951  1.0
  P  P7  1  0.746  0.460  0.049  1.0
  P  P8  1  0.460  0.049  0.746  1.0
  P  P9  1  0.049  0.746  0.460  1.0
  P  P10  1  0.951  0.254  0.547  1.0
  P  P11  1  0.547  0.951  0.254  1.0
  O  O12  1  0.900  0.685  0.485  1.0
  O  O13  1  0.685  0.485  0.900  1.0
  O  O14  1  0.941  0.090  0.739  1.0
  O  O15  1  0.485  0.900  0.685  1.0
  O  O16  1  0.990  0.183  0.389  1.0
  O  O17  1  0.753  0.407  0.556  1.0
  O  O18  1  0.739  0.941  0.090  1.0
  O  O19  1  0.556  0.753  0.407  1.0
  O  O20  1  0.819  0.610  0.009  1.0
  O  O21  1  0.407  0.556  0.753  1.0
  O  O22  1  0.911  0.254  0.069  1.0
  O  O23  1  0.610  0.009  0.819  1.0
  O  O24  1  0.389  0.990  0.183  1.0
  O  O25  1  0.090  0.739  0.941  1.0
  O  O26  1  0.593  0.438  0.253  1.0
  O  O27  1  0.183  0.389  0.990  1.0
  O  O28  1  0.438  0.253  0.593  1.0
  O  O29  1  0.254  0.069  0.911  1.0
  O  O30  1  0.253  0.593  0.438  1.0
  O  O31  1  0.009  0.819  0.610  1.0
  O  O32  1  0.497  0.109  0.320  1.0
  O  O33  1  0.069  0.911  0.254  1.0
  O  O34  1  0.320  0.497  0.109  1.0
  O  O35  1  0.109  0.320  0.497  1.0
[/CIF]
.