The structure described by Rb4Co(PO4)6 crystallizes in the monoclinic C2/m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), two equivalent O(6), and two equivalent O(8) atoms. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(7) atoms. Co(1) is bonded to two equivalent O(5) and four equivalent O(7) atoms to form CoO6 octahedra that share corners with two 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(2), one O(3), and one O(4) atom to form corner-sharing PO4 tetrahedra. In the second P site, P(2) is bonded to one O(5), one O(6), and two equivalent O(2) atoms to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), and one P(1) atom. In the second O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(2) atom. In the third O site, O(6) is bonded in a single-bond geometry to one Rb(2), two equivalent Rb(1), and one P(2) atom. In the fourth O site, O(7) is bonded in a distorted single-bond geometry to one Rb(2) and one Co(1) atom. In the fifth O site, O(8) is bonded in a 3-coordinate geometry to two equivalent Rb(1) and one O(8) atom. In the sixth O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Rb(2) and two equivalent P(1) atoms. In the seventh O site, O(2) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the eighth O site, O(3) is bonded in a single-bond geometry to one Rb(1), one Rb(2), and one P(1) atom. is represented by the CIF file [CIF]
data_Rb4Co(PO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.820
_cell_length_b   8.820
_cell_length_c   9.748
_cell_angle_alpha   108.807
_cell_angle_beta   115.611
_cell_angle_gamma   99.553
_symmetry_Int_Tables_number   1
_cell_volume   604.468
_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
  Rb  Rb0  1  0.225  0.725  0.500  1.0
  Rb  Rb1  1  0.775  0.275  0.500  1.0
  Rb  Rb2  1  0.278  0.675  0.953  1.0
  Rb  Rb3  1  0.722  0.325  0.047  1.0
  Co  Co4  1  0.000  0.000  0.000  1.0
  P  P5  1  0.499  0.483  0.715  1.0
  P  P6  1  0.232  0.215  0.715  1.0
  P  P7  1  0.501  0.517  0.285  1.0
  P  P8  1  0.768  0.785  0.285  1.0
  P  P9  1  0.158  0.237  0.395  1.0
  P  P10  1  0.843  0.763  0.605  1.0
  O  O11  1  0.416  0.374  0.790  1.0
  O  O12  1  0.584  0.626  0.210  1.0
  O  O13  1  0.367  0.362  0.510  1.0
  O  O14  1  0.148  0.143  0.510  1.0
  O  O15  1  0.633  0.638  0.490  1.0
  O  O16  1  0.852  0.857  0.490  1.0
  O  O17  1  0.682  0.475  0.764  1.0
  O  O18  1  0.289  0.082  0.764  1.0
  O  O19  1  0.318  0.525  0.236  1.0
  O  O20  1  0.711  0.918  0.236  1.0
  O  O21  1  0.469  0.649  0.762  1.0
  O  O22  1  0.113  0.293  0.762  1.0
  O  O23  1  0.531  0.351  0.238  1.0
  O  O24  1  0.887  0.707  0.238  1.0
  O  O25  1  0.150  0.097  0.247  1.0
  O  O26  1  0.850  0.903  0.753  1.0
  O  O27  1  0.033  0.335  0.368  1.0
  O  O28  1  0.967  0.665  0.632  1.0
  O  O29  1  0.005  0.800  0.994  1.0
  O  O30  1  0.194  0.989  0.994  1.0
  O  O31  1  0.995  0.200  0.006  1.0
  O  O32  1  0.806  0.011  0.006  1.0
  O  O33  1  0.454  0.967  0.422  1.0
  O  O34  1  0.546  0.033  0.578  1.0
[/CIF]
.
The structure described by Rb4Co(PO4)6 crystallizes in the monoclinic C2/m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), two equivalent O(6), and two equivalent O(8) atoms. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(7) atoms. Co(1) is bonded to two equivalent O(5) and four equivalent O(7) atoms to form CoO6 octahedra that share corners with two 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(2), one O(3), and one O(4) atom to form corner-sharing PO4 tetrahedra. In the second P site, P(2) is bonded to one O(5), one O(6), and two equivalent O(2) atoms to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), and one P(1) atom. In the second O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(2) atom. In the third O site, O(6) is bonded in a single-bond geometry to one Rb(2), two equivalent Rb(1), and one P(2) atom. In the fourth O site, O(7) is bonded in a distorted single-bond geometry to one Rb(2) and one Co(1) atom. In the fifth O site, O(8) is bonded in a 3-coordinate geometry to two equivalent Rb(1) and one O(8) atom. In the sixth O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Rb(2) and two equivalent P(1) atoms. In the seventh O site, O(2) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the eighth O site, O(3) is bonded in a single-bond geometry to one Rb(1), one Rb(2), and one P(1) atom. is represented by the CIF file [CIF]
data_Rb4Co(PO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.820
_cell_length_b   8.820
_cell_length_c   9.748
_cell_angle_alpha   108.807
_cell_angle_beta   115.611
_cell_angle_gamma   99.553
_symmetry_Int_Tables_number   1
_cell_volume   604.468
_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
  Rb  Rb0  1  0.225  0.725  0.500  1.0
  Rb  Rb1  1  0.775  0.275  0.500  1.0
  Rb  Rb2  1  0.278  0.675  0.953  1.0
  Rb  Rb3  1  0.722  0.325  0.047  1.0
  Co  Co4  1  0.000  0.000  0.000  1.0
  P  P5  1  0.499  0.483  0.715  1.0
  P  P6  1  0.232  0.215  0.715  1.0
  P  P7  1  0.501  0.517  0.285  1.0
  P  P8  1  0.768  0.785  0.285  1.0
  P  P9  1  0.158  0.237  0.395  1.0
  P  P10  1  0.843  0.763  0.605  1.0
  O  O11  1  0.416  0.374  0.790  1.0
  O  O12  1  0.584  0.626  0.210  1.0
  O  O13  1  0.367  0.362  0.510  1.0
  O  O14  1  0.148  0.143  0.510  1.0
  O  O15  1  0.633  0.638  0.490  1.0
  O  O16  1  0.852  0.857  0.490  1.0
  O  O17  1  0.682  0.475  0.764  1.0
  O  O18  1  0.289  0.082  0.764  1.0
  O  O19  1  0.318  0.525  0.236  1.0
  O  O20  1  0.711  0.918  0.236  1.0
  O  O21  1  0.469  0.649  0.762  1.0
  O  O22  1  0.113  0.293  0.762  1.0
  O  O23  1  0.531  0.351  0.238  1.0
  O  O24  1  0.887  0.707  0.238  1.0
  O  O25  1  0.150  0.097  0.247  1.0
  O  O26  1  0.850  0.903  0.753  1.0
  O  O27  1  0.033  0.335  0.368  1.0
  O  O28  1  0.967  0.665  0.632  1.0
  O  O29  1  0.005  0.800  0.994  1.0
  O  O30  1  0.194  0.989  0.994  1.0
  O  O31  1  0.995  0.200  0.006  1.0
  O  O32  1  0.806  0.011  0.006  1.0
  O  O33  1  0.454  0.967  0.422  1.0
  O  O34  1  0.546  0.033  0.578  1.0
[/CIF]
.