The structure described by Co7(AsO6)2 crystallizes in the triclinic P-1 space group. There are eight inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(12), one O(4), and one O(8) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(5)O6 octahedra,  a cornercorner with one As(3)O6 octahedra, corners with two equivalent Co(2)O6 octahedra, corners with two equivalent Co(3)O6 octahedra, corners with two equivalent Co(4)O6 octahedra, corners with two equivalent As(2)O6 octahedra, and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-66°. In the second Co site, Co(2) is bonded to one O(10), one O(4), one O(6), one O(7), one O(8), and one O(9) atom to form CoO6 octahedra that share corners with two equivalent Co(6)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with two equivalent Co(7)O4 tetrahedra,  an edgeedge with one Co(4)O6 octahedra,  an edgeedge with one Co(5)O6 octahedra,  an edgeedge with one Co(8)O6 octahedra,  an edgeedge with one As(2)O6 octahedra,  an edgeedge with one As(3)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. In the third Co site, Co(3) is bonded to one O(1), one O(10), one O(4), one O(5), one O(6), and one O(9) atom to form CoO6 octahedra that share corners with two equivalent Co(8)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with two equivalent Co(7)O4 tetrahedra,  an edgeedge with one Co(4)O6 octahedra,  an edgeedge with one Co(5)O6 octahedra,  an edgeedge with one Co(6)O6 octahedra,  an edgeedge with one As(2)O6 octahedra,  an edgeedge with one As(3)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. In the fourth Co site, Co(4) is bonded to one O(1), one O(11), one O(2), one O(3), one O(8), and one O(9) atom to form CoO6 octahedra that share  a cornercorner with one Co(7)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra,  an edgeedge with one Co(5)O6 octahedra,  an edgeedge with one Co(6)O6 octahedra,  an edgeedge with one Co(8)O6 octahedra, and  an edgeedge with one As(2)O6 octahedra. In the fifth Co site, Co(5) is bonded to one O(10), one O(12), one O(2), one O(3), one O(5), and one O(7) atom to form CoO6 octahedra that share  a cornercorner with one Co(1)O4 tetrahedra, corners with two equivalent Co(7)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra,  an edgeedge with one Co(6)O6 octahedra,  an edgeedge with one Co(8)O6 octahedra, and  an edgeedge with one As(3)O6 octahedra. In the sixth Co site, Co(6) is bonded to two equivalent O(10), two equivalent O(2), and two equivalent O(9) atoms to form CoO6 octahedra that share corners with four equivalent Co(2)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, edges with two equivalent Co(3)O6 octahedra, edges with two equivalent Co(4)O6 octahedra, edges with two equivalent Co(5)O6 octahedra, and edges with two equivalent Co(8)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. In the seventh Co site, Co(7) is bonded to one O(11), one O(5), one O(6), and one O(7) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one As(2)O6 octahedra, corners with two equivalent Co(2)O6 octahedra, corners with two equivalent Co(3)O6 octahedra, corners with two equivalent Co(5)O6 octahedra, corners with two equivalent As(3)O6 octahedra, and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-65°. In the eighth Co site, Co(8) is bonded to two equivalent O(10), two equivalent O(3), and two equivalent O(9) atoms to form CoO6 octahedra that share corners with four equivalent Co(3)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, edges with two equivalent Co(2)O6 octahedra, edges with two equivalent Co(4)O6 octahedra, edges with two equivalent Co(5)O6 octahedra, and edges with two equivalent Co(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. There are three inequivalent As sites. In the first As site, As(1) is bonded to one O(11), one O(12), one O(2), and one O(3) atom to form AsO4 tetrahedra that share  a cornercorner with one Co(6)O6 octahedra,  a cornercorner with one Co(8)O6 octahedra, corners with three equivalent Co(4)O6 octahedra, corners with three equivalent Co(5)O6 octahedra,  a cornercorner with one Co(1)O4 tetrahedra, and  a cornercorner with one Co(7)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-57°. In the second As site, As(2) is bonded to two equivalent O(1), two equivalent O(6), and two equivalent O(8) atoms to form AsO6 octahedra that share corners with two equivalent Co(7)O4 tetrahedra, corners with four equivalent Co(1)O4 tetrahedra, edges with two equivalent Co(2)O6 octahedra, edges with two equivalent Co(3)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. In the third As site, As(3) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(7) atoms to form AsO6 octahedra that share corners with two equivalent Co(1)O4 tetrahedra, corners with four equivalent Co(7)O4 tetrahedra, edges with two equivalent Co(2)O6 octahedra, edges with two equivalent Co(3)O6 octahedra, and edges with two equivalent Co(5)O6 octahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(3), one Co(4), and one As(2) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Co(4), one Co(5), one Co(6), and one As(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Co(4), one Co(5), one Co(8), and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), one Co(2), one Co(3), and one As(3) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Co(3), one Co(5), one Co(7), and one As(3) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Co(2), one Co(3), one Co(7), and one As(2) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Co(2), one Co(5), one Co(7), and one As(3) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(2), one Co(4), and one As(2) atom. In the ninth O site, O(9) is bonded to one Co(2), one Co(3), one Co(4), one Co(6), and one Co(8) atom to form a mixture of corner and edge-sharing OCo5 square pyramids. In the tenth O site, O(10) is bonded to one Co(2), one Co(3), one Co(5), one Co(6), and one Co(8) atom to form a mixture of corner and edge-sharing OCo5 square pyramids. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Co(4), one Co(7), and one As(1) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Co(1), one Co(5), and one As(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Co7(AsO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.882
_cell_length_b   8.462
_cell_length_c   10.522
_cell_angle_alpha   114.388
_cell_angle_beta   106.308
_cell_angle_gamma   90.013
_symmetry_Int_Tables_number   1
_cell_volume   453.800
_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
  Co  Co0  1  0.427  0.798  0.855  1.0
  Co  Co1  1  0.156  0.156  0.818  1.0
  Co  Co2  1  0.661  0.156  0.818  1.0
  Co  Co3  1  0.837  0.826  0.675  1.0
  Co  Co4  1  0.339  0.844  0.182  1.0
  Co  Co5  1  0.163  0.174  0.325  1.0
  Co  Co6  1  0.573  0.202  0.145  1.0
  Co  Co7  1  0.664  0.649  0.329  1.0
  Co  Co8  1  0.500  0.000  0.500  1.0
  Co  Co9  1  0.844  0.844  0.182  1.0
  Co  Co10  1  0.336  0.351  0.671  1.0
  Co  Co11  1  0.074  0.448  0.148  1.0
  Co  Co12  1  0.926  0.552  0.852  1.0
  Co  Co13  1  0.000  0.000  0.500  1.0
  As  As14  1  0.750  0.374  0.499  1.0
  As  As15  1  0.250  0.626  0.501  1.0
  As  As16  1  0.000  0.000  0.000  1.0
  As  As17  1  0.500  0.500  0.000  1.0
  O  O18  1  0.702  0.922  0.849  1.0
  O  O19  1  0.496  0.744  0.502  1.0
  O  O20  1  0.006  0.744  0.502  1.0
  O  O21  1  0.510  0.733  0.020  1.0
  O  O22  1  0.646  0.425  0.849  1.0
  O  O23  1  0.991  0.213  0.983  1.0
  O  O24  1  0.504  0.256  0.498  1.0
  O  O25  1  0.203  0.425  0.848  1.0
  O  O26  1  0.147  0.922  0.850  1.0
  O  O27  1  0.171  0.946  0.342  1.0
  O  O28  1  0.671  0.893  0.342  1.0
  O  O29  1  0.354  0.575  0.151  1.0
  O  O30  1  0.298  0.078  0.151  1.0
  O  O31  1  0.490  0.267  0.980  1.0
  O  O32  1  0.829  0.569  0.659  1.0
  O  O33  1  0.329  0.589  0.659  1.0
  O  O34  1  0.994  0.256  0.498  1.0
  O  O35  1  0.171  0.431  0.341  1.0
  O  O36  1  0.671  0.411  0.341  1.0
  O  O37  1  0.853  0.078  0.150  1.0
  O  O38  1  0.829  0.054  0.658  1.0
  O  O39  1  0.009  0.787  0.017  1.0
  O  O40  1  0.797  0.575  0.152  1.0
  O  O41  1  0.329  0.107  0.658  1.0
[/CIF]
.
The structure described by Co7(AsO6)2 crystallizes in the triclinic P-1 space group. There are eight inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(12), one O(4), and one O(8) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(5)O6 octahedra,  a cornercorner with one As(3)O6 octahedra, corners with two equivalent Co(2)O6 octahedra, corners with two equivalent Co(3)O6 octahedra, corners with two equivalent Co(4)O6 octahedra, corners with two equivalent As(2)O6 octahedra, and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-66°. In the second Co site, Co(2) is bonded to one O(10), one O(4), one O(6), one O(7), one O(8), and one O(9) atom to form CoO6 octahedra that share corners with two equivalent Co(6)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with two equivalent Co(7)O4 tetrahedra,  an edgeedge with one Co(4)O6 octahedra,  an edgeedge with one Co(5)O6 octahedra,  an edgeedge with one Co(8)O6 octahedra,  an edgeedge with one As(2)O6 octahedra,  an edgeedge with one As(3)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. In the third Co site, Co(3) is bonded to one O(1), one O(10), one O(4), one O(5), one O(6), and one O(9) atom to form CoO6 octahedra that share corners with two equivalent Co(8)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with two equivalent Co(7)O4 tetrahedra,  an edgeedge with one Co(4)O6 octahedra,  an edgeedge with one Co(5)O6 octahedra,  an edgeedge with one Co(6)O6 octahedra,  an edgeedge with one As(2)O6 octahedra,  an edgeedge with one As(3)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. In the fourth Co site, Co(4) is bonded to one O(1), one O(11), one O(2), one O(3), one O(8), and one O(9) atom to form CoO6 octahedra that share  a cornercorner with one Co(7)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra,  an edgeedge with one Co(5)O6 octahedra,  an edgeedge with one Co(6)O6 octahedra,  an edgeedge with one Co(8)O6 octahedra, and  an edgeedge with one As(2)O6 octahedra. In the fifth Co site, Co(5) is bonded to one O(10), one O(12), one O(2), one O(3), one O(5), and one O(7) atom to form CoO6 octahedra that share  a cornercorner with one Co(1)O4 tetrahedra, corners with two equivalent Co(7)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra,  an edgeedge with one Co(6)O6 octahedra,  an edgeedge with one Co(8)O6 octahedra, and  an edgeedge with one As(3)O6 octahedra. In the sixth Co site, Co(6) is bonded to two equivalent O(10), two equivalent O(2), and two equivalent O(9) atoms to form CoO6 octahedra that share corners with four equivalent Co(2)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, edges with two equivalent Co(3)O6 octahedra, edges with two equivalent Co(4)O6 octahedra, edges with two equivalent Co(5)O6 octahedra, and edges with two equivalent Co(8)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. In the seventh Co site, Co(7) is bonded to one O(11), one O(5), one O(6), and one O(7) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one As(2)O6 octahedra, corners with two equivalent Co(2)O6 octahedra, corners with two equivalent Co(3)O6 octahedra, corners with two equivalent Co(5)O6 octahedra, corners with two equivalent As(3)O6 octahedra, and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-65°. In the eighth Co site, Co(8) is bonded to two equivalent O(10), two equivalent O(3), and two equivalent O(9) atoms to form CoO6 octahedra that share corners with four equivalent Co(3)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, edges with two equivalent Co(2)O6 octahedra, edges with two equivalent Co(4)O6 octahedra, edges with two equivalent Co(5)O6 octahedra, and edges with two equivalent Co(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. There are three inequivalent As sites. In the first As site, As(1) is bonded to one O(11), one O(12), one O(2), and one O(3) atom to form AsO4 tetrahedra that share  a cornercorner with one Co(6)O6 octahedra,  a cornercorner with one Co(8)O6 octahedra, corners with three equivalent Co(4)O6 octahedra, corners with three equivalent Co(5)O6 octahedra,  a cornercorner with one Co(1)O4 tetrahedra, and  a cornercorner with one Co(7)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-57°. In the second As site, As(2) is bonded to two equivalent O(1), two equivalent O(6), and two equivalent O(8) atoms to form AsO6 octahedra that share corners with two equivalent Co(7)O4 tetrahedra, corners with four equivalent Co(1)O4 tetrahedra, edges with two equivalent Co(2)O6 octahedra, edges with two equivalent Co(3)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. In the third As site, As(3) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(7) atoms to form AsO6 octahedra that share corners with two equivalent Co(1)O4 tetrahedra, corners with four equivalent Co(7)O4 tetrahedra, edges with two equivalent Co(2)O6 octahedra, edges with two equivalent Co(3)O6 octahedra, and edges with two equivalent Co(5)O6 octahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(3), one Co(4), and one As(2) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Co(4), one Co(5), one Co(6), and one As(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Co(4), one Co(5), one Co(8), and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), one Co(2), one Co(3), and one As(3) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Co(3), one Co(5), one Co(7), and one As(3) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Co(2), one Co(3), one Co(7), and one As(2) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Co(2), one Co(5), one Co(7), and one As(3) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(2), one Co(4), and one As(2) atom. In the ninth O site, O(9) is bonded to one Co(2), one Co(3), one Co(4), one Co(6), and one Co(8) atom to form a mixture of corner and edge-sharing OCo5 square pyramids. In the tenth O site, O(10) is bonded to one Co(2), one Co(3), one Co(5), one Co(6), and one Co(8) atom to form a mixture of corner and edge-sharing OCo5 square pyramids. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Co(4), one Co(7), and one As(1) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Co(1), one Co(5), and one As(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Co7(AsO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.882
_cell_length_b   8.462
_cell_length_c   10.522
_cell_angle_alpha   114.388
_cell_angle_beta   106.308
_cell_angle_gamma   90.013
_symmetry_Int_Tables_number   1
_cell_volume   453.800
_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
  Co  Co0  1  0.427  0.798  0.855  1.0
  Co  Co1  1  0.156  0.156  0.818  1.0
  Co  Co2  1  0.661  0.156  0.818  1.0
  Co  Co3  1  0.837  0.826  0.675  1.0
  Co  Co4  1  0.339  0.844  0.182  1.0
  Co  Co5  1  0.163  0.174  0.325  1.0
  Co  Co6  1  0.573  0.202  0.145  1.0
  Co  Co7  1  0.664  0.649  0.329  1.0
  Co  Co8  1  0.500  0.000  0.500  1.0
  Co  Co9  1  0.844  0.844  0.182  1.0
  Co  Co10  1  0.336  0.351  0.671  1.0
  Co  Co11  1  0.074  0.448  0.148  1.0
  Co  Co12  1  0.926  0.552  0.852  1.0
  Co  Co13  1  0.000  0.000  0.500  1.0
  As  As14  1  0.750  0.374  0.499  1.0
  As  As15  1  0.250  0.626  0.501  1.0
  As  As16  1  0.000  0.000  0.000  1.0
  As  As17  1  0.500  0.500  0.000  1.0
  O  O18  1  0.702  0.922  0.849  1.0
  O  O19  1  0.496  0.744  0.502  1.0
  O  O20  1  0.006  0.744  0.502  1.0
  O  O21  1  0.510  0.733  0.020  1.0
  O  O22  1  0.646  0.425  0.849  1.0
  O  O23  1  0.991  0.213  0.983  1.0
  O  O24  1  0.504  0.256  0.498  1.0
  O  O25  1  0.203  0.425  0.848  1.0
  O  O26  1  0.147  0.922  0.850  1.0
  O  O27  1  0.171  0.946  0.342  1.0
  O  O28  1  0.671  0.893  0.342  1.0
  O  O29  1  0.354  0.575  0.151  1.0
  O  O30  1  0.298  0.078  0.151  1.0
  O  O31  1  0.490  0.267  0.980  1.0
  O  O32  1  0.829  0.569  0.659  1.0
  O  O33  1  0.329  0.589  0.659  1.0
  O  O34  1  0.994  0.256  0.498  1.0
  O  O35  1  0.171  0.431  0.341  1.0
  O  O36  1  0.671  0.411  0.341  1.0
  O  O37  1  0.853  0.078  0.150  1.0
  O  O38  1  0.829  0.054  0.658  1.0
  O  O39  1  0.009  0.787  0.017  1.0
  O  O40  1  0.797  0.575  0.152  1.0
  O  O41  1  0.329  0.107  0.658  1.0
[/CIF]
.