The crystal structure described by Cu9(PO4)8 crystallizes in the triclinic P-1 space group. There are six inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(10), one O(16), one O(5), one O(8), and one O(9) atom to form distorted CuO5 square pyramids that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and  an edgeedge with one P(3)O4 tetrahedra. In the second Cu site, Cu(2) is bonded in a distorted rectangular see-saw-like geometry to one O(13), one O(14), one O(3), and one O(4) atom. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one O(11), one O(12), one O(14), and one O(15) atom. In the fourth Cu site, Cu(4) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(8) atoms. In the fifth Cu site, Cu(5) is bonded in a square co-planar geometry to two equivalent O(16) and two equivalent O(7) atoms. In the sixth Cu site, Cu(6) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(6) atoms. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(11), one O(14), one O(3), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Cu(1)O5 square pyramid. In the second P site, P(2) is bonded to one O(10), one O(12), one O(2), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Cu(1)O5 square pyramid. In the third P site, P(3) is bonded to one O(15), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share  an edgeedge with one Cu(1)O5 square pyramid. In the fourth P site, P(4) is bonded to one O(1), one O(13), one O(16), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Cu(1)O5 square pyramid. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cu(4) and one P(4) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cu(6) and one P(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Cu(2) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Cu(2) and one P(4) atom. In the fifth O site, O(5) is bonded in an L-shaped geometry to one Cu(1) and one P(3) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Cu(6) and one P(3) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cu(5) and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(4), and one P(3) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(1) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(2) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Cu(3) and one P(1) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Cu(3) and one P(2) atom. In the thirteenth O site, O(13) is bonded in a bent 120 degrees geometry to one Cu(2) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Cu(2), one Cu(3), and one P(1) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 120 degrees geometry to one Cu(3) and one P(3) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Cu(1), one Cu(5), and one P(4) atom. is represented by the CIF file [CIF]
data_Cu9(PO4)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.791
_cell_length_b   8.962
_cell_length_c   9.167
_cell_angle_alpha   111.440
_cell_angle_beta   99.468
_cell_angle_gamma   106.542
_symmetry_Int_Tables_number   1
_cell_volume   614.546
_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
  Cu  Cu0  1  0.791  0.275  0.069  1.0
  Cu  Cu1  1  0.716  0.889  0.441  1.0
  Cu  Cu2  1  0.351  0.686  0.445  1.0
  Cu  Cu3  1  0.000  0.500  0.500  1.0
  Cu  Cu4  1  0.649  0.314  0.555  1.0
  Cu  Cu5  1  0.000  0.000  0.000  1.0
  Cu  Cu6  1  0.284  0.111  0.559  1.0
  Cu  Cu7  1  0.209  0.725  0.931  1.0
  Cu  Cu8  1  0.500  0.500  0.000  1.0
  P  P9  1  0.597  0.068  0.713  1.0
  P  P10  1  0.836  0.624  0.899  1.0
  P  P11  1  0.350  0.579  0.734  1.0
  P  P12  1  0.030  0.881  0.649  1.0
  P  P13  1  0.970  0.119  0.351  1.0
  P  P14  1  0.650  0.421  0.266  1.0
  P  P15  1  0.164  0.376  0.101  1.0
  P  P16  1  0.403  0.932  0.287  1.0
  O  O17  1  0.090  0.742  0.549  1.0
  O  O18  1  0.286  0.483  0.040  1.0
  O  O19  1  0.570  0.911  0.279  1.0
  O  O20  1  0.881  0.939  0.344  1.0
  O  O21  1  0.585  0.244  0.110  1.0
  O  O22  1  0.594  0.555  0.228  1.0
  O  O23  1  0.185  0.200  0.061  1.0
  O  O24  1  0.845  0.461  0.288  1.0
  O  O25  1  0.309  0.930  0.130  1.0
  O  O26  1  0.691  0.070  0.870  1.0
  O  O27  1  0.984  0.343  0.010  1.0
  O  O28  1  0.714  0.517  0.960  1.0
  O  O29  1  0.430  0.089  0.721  1.0
  O  O30  1  0.119  0.061  0.656  1.0
  O  O31  1  0.415  0.756  0.890  1.0
  O  O32  1  0.406  0.445  0.772  1.0
  O  O33  1  0.815  0.800  0.939  1.0
  O  O34  1  0.155  0.539  0.712  1.0
  O  O35  1  0.716  0.203  0.675  1.0
  O  O36  1  0.284  0.797  0.325  1.0
  O  O37  1  0.805  0.532  0.709  1.0
  O  O38  1  0.160  0.164  0.413  1.0
  O  O39  1  0.442  0.118  0.433  1.0
  O  O40  1  0.399  0.582  0.583  1.0
  O  O41  1  0.068  0.885  0.824  1.0
  O  O42  1  0.910  0.258  0.451  1.0
  O  O43  1  0.601  0.418  0.417  1.0
  O  O44  1  0.558  0.882  0.567  1.0
  O  O45  1  0.840  0.836  0.587  1.0
  O  O46  1  0.195  0.468  0.291  1.0
  O  O47  1  0.932  0.115  0.176  1.0
  O  O48  1  0.016  0.657  0.990  1.0
[/CIF]
.
The crystal structure described by Cu9(PO4)8 crystallizes in the triclinic P-1 space group. There are six inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(10), one O(16), one O(5), one O(8), and one O(9) atom to form distorted CuO5 square pyramids that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and  an edgeedge with one P(3)O4 tetrahedra. In the second Cu site, Cu(2) is bonded in a distorted rectangular see-saw-like geometry to one O(13), one O(14), one O(3), and one O(4) atom. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one O(11), one O(12), one O(14), and one O(15) atom. In the fourth Cu site, Cu(4) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(8) atoms. In the fifth Cu site, Cu(5) is bonded in a square co-planar geometry to two equivalent O(16) and two equivalent O(7) atoms. In the sixth Cu site, Cu(6) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(6) atoms. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(11), one O(14), one O(3), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Cu(1)O5 square pyramid. In the second P site, P(2) is bonded to one O(10), one O(12), one O(2), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Cu(1)O5 square pyramid. In the third P site, P(3) is bonded to one O(15), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share  an edgeedge with one Cu(1)O5 square pyramid. In the fourth P site, P(4) is bonded to one O(1), one O(13), one O(16), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Cu(1)O5 square pyramid. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cu(4) and one P(4) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cu(6) and one P(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Cu(2) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Cu(2) and one P(4) atom. In the fifth O site, O(5) is bonded in an L-shaped geometry to one Cu(1) and one P(3) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Cu(6) and one P(3) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cu(5) and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(4), and one P(3) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(1) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(2) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Cu(3) and one P(1) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Cu(3) and one P(2) atom. In the thirteenth O site, O(13) is bonded in a bent 120 degrees geometry to one Cu(2) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Cu(2), one Cu(3), and one P(1) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 120 degrees geometry to one Cu(3) and one P(3) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Cu(1), one Cu(5), and one P(4) atom. is represented by the CIF file [CIF]
data_Cu9(PO4)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.791
_cell_length_b   8.962
_cell_length_c   9.167
_cell_angle_alpha   111.440
_cell_angle_beta   99.468
_cell_angle_gamma   106.542
_symmetry_Int_Tables_number   1
_cell_volume   614.546
_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
  Cu  Cu0  1  0.791  0.275  0.069  1.0
  Cu  Cu1  1  0.716  0.889  0.441  1.0
  Cu  Cu2  1  0.351  0.686  0.445  1.0
  Cu  Cu3  1  0.000  0.500  0.500  1.0
  Cu  Cu4  1  0.649  0.314  0.555  1.0
  Cu  Cu5  1  0.000  0.000  0.000  1.0
  Cu  Cu6  1  0.284  0.111  0.559  1.0
  Cu  Cu7  1  0.209  0.725  0.931  1.0
  Cu  Cu8  1  0.500  0.500  0.000  1.0
  P  P9  1  0.597  0.068  0.713  1.0
  P  P10  1  0.836  0.624  0.899  1.0
  P  P11  1  0.350  0.579  0.734  1.0
  P  P12  1  0.030  0.881  0.649  1.0
  P  P13  1  0.970  0.119  0.351  1.0
  P  P14  1  0.650  0.421  0.266  1.0
  P  P15  1  0.164  0.376  0.101  1.0
  P  P16  1  0.403  0.932  0.287  1.0
  O  O17  1  0.090  0.742  0.549  1.0
  O  O18  1  0.286  0.483  0.040  1.0
  O  O19  1  0.570  0.911  0.279  1.0
  O  O20  1  0.881  0.939  0.344  1.0
  O  O21  1  0.585  0.244  0.110  1.0
  O  O22  1  0.594  0.555  0.228  1.0
  O  O23  1  0.185  0.200  0.061  1.0
  O  O24  1  0.845  0.461  0.288  1.0
  O  O25  1  0.309  0.930  0.130  1.0
  O  O26  1  0.691  0.070  0.870  1.0
  O  O27  1  0.984  0.343  0.010  1.0
  O  O28  1  0.714  0.517  0.960  1.0
  O  O29  1  0.430  0.089  0.721  1.0
  O  O30  1  0.119  0.061  0.656  1.0
  O  O31  1  0.415  0.756  0.890  1.0
  O  O32  1  0.406  0.445  0.772  1.0
  O  O33  1  0.815  0.800  0.939  1.0
  O  O34  1  0.155  0.539  0.712  1.0
  O  O35  1  0.716  0.203  0.675  1.0
  O  O36  1  0.284  0.797  0.325  1.0
  O  O37  1  0.805  0.532  0.709  1.0
  O  O38  1  0.160  0.164  0.413  1.0
  O  O39  1  0.442  0.118  0.433  1.0
  O  O40  1  0.399  0.582  0.583  1.0
  O  O41  1  0.068  0.885  0.824  1.0
  O  O42  1  0.910  0.258  0.451  1.0
  O  O43  1  0.601  0.418  0.417  1.0
  O  O44  1  0.558  0.882  0.567  1.0
  O  O45  1  0.840  0.836  0.587  1.0
  O  O46  1  0.195  0.468  0.291  1.0
  O  O47  1  0.932  0.115  0.176  1.0
  O  O48  1  0.016  0.657  0.990  1.0
[/CIF]
.