The material structure described by Ca(PO4)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to one O(2), one O(3), one O(6), one O(7), one O(8), and two equivalent O(5) atoms to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Ca(1)O7 pentagonal bipyramid. 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 PO4 tetrahedra that share corners with two equivalent Ca(1)O7 pentagonal bipyramids and corners with two equivalent P(2)O4 tetrahedra. In the second P site, P(2) is bonded to one O(1), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Ca(1)O7 pentagonal bipyramids and corners with two equivalent P(1)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(6) is bonded in a distorted linear geometry to one Ca(1) and one P(2) atom. In the second O site, O(7) is bonded in a single-bond geometry to one Ca(1) atom. In the third O site, O(8) is bonded in a single-bond geometry to one Ca(1) atom. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one P(1) atom. In the sixth O site, O(3) is bonded in a bent 150 degrees geometry to one Ca(1) and one P(1) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the eighth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one P(2) atom. is represented by the CIF file [CIF]
data_Ca(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.519
_cell_length_b   7.627
_cell_length_c   12.550
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   107.635
_symmetry_Int_Tables_number   1
_cell_volume   685.947
_cell_formula_units_Z   4
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  0.984  0.836  0.885  1.0
  Ca  Ca1  1  0.484  0.336  0.615  1.0
  Ca  Ca2  1  0.016  0.164  0.115  1.0
  Ca  Ca3  1  0.516  0.664  0.385  1.0
  P  P4  1  0.287  0.598  0.016  1.0
  P  P5  1  0.787  0.098  0.484  1.0
  P  P6  1  0.713  0.402  0.984  1.0
  P  P7  1  0.213  0.902  0.516  1.0
  P  P8  1  0.325  0.281  0.897  1.0
  P  P9  1  0.825  0.781  0.603  1.0
  P  P10  1  0.675  0.719  0.103  1.0
  P  P11  1  0.175  0.219  0.397  1.0
  O  O12  1  0.506  0.712  0.023  1.0
  O  O13  1  0.006  0.212  0.477  1.0
  O  O14  1  0.494  0.288  0.977  1.0
  O  O15  1  0.994  0.788  0.523  1.0
  O  O16  1  0.227  0.471  0.109  1.0
  O  O17  1  0.727  0.971  0.391  1.0
  O  O18  1  0.773  0.529  0.891  1.0
  O  O19  1  0.273  0.029  0.609  1.0
  O  O20  1  0.185  0.733  0.988  1.0
  O  O21  1  0.685  0.233  0.512  1.0
  O  O22  1  0.815  0.267  0.012  1.0
  O  O23  1  0.315  0.767  0.488  1.0
  O  O24  1  0.287  0.478  0.909  1.0
  O  O25  1  0.787  0.978  0.591  1.0
  O  O26  1  0.713  0.522  0.091  1.0
  O  O27  1  0.213  0.022  0.409  1.0
  O  O28  1  0.161  0.134  0.943  1.0
  O  O29  1  0.661  0.634  0.557  1.0
  O  O30  1  0.839  0.866  0.057  1.0
  O  O31  1  0.339  0.366  0.443  1.0
  O  O32  1  0.879  0.768  0.716  1.0
  O  O33  1  0.379  0.268  0.784  1.0
  O  O34  1  0.121  0.232  0.284  1.0
  O  O35  1  0.621  0.732  0.216  1.0
  O  O36  1  0.747  0.029  0.845  1.0
  O  O37  1  0.247  0.529  0.655  1.0
  O  O38  1  0.253  0.971  0.155  1.0
  O  O39  1  0.753  0.471  0.345  1.0
  O  O40  1  0.787  0.346  0.720  1.0
  O  O41  1  0.287  0.846  0.780  1.0
  O  O42  1  0.213  0.654  0.280  1.0
  O  O43  1  0.713  0.154  0.220  1.0
[/CIF]
.
The material structure described by Ca(PO4)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to one O(2), one O(3), one O(6), one O(7), one O(8), and two equivalent O(5) atoms to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Ca(1)O7 pentagonal bipyramid. 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 PO4 tetrahedra that share corners with two equivalent Ca(1)O7 pentagonal bipyramids and corners with two equivalent P(2)O4 tetrahedra. In the second P site, P(2) is bonded to one O(1), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Ca(1)O7 pentagonal bipyramids and corners with two equivalent P(1)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(6) is bonded in a distorted linear geometry to one Ca(1) and one P(2) atom. In the second O site, O(7) is bonded in a single-bond geometry to one Ca(1) atom. In the third O site, O(8) is bonded in a single-bond geometry to one Ca(1) atom. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one P(1) atom. In the sixth O site, O(3) is bonded in a bent 150 degrees geometry to one Ca(1) and one P(1) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the eighth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one P(2) atom. is represented by the CIF file [CIF]
data_Ca(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.519
_cell_length_b   7.627
_cell_length_c   12.550
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   107.635
_symmetry_Int_Tables_number   1
_cell_volume   685.947
_cell_formula_units_Z   4
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  0.984  0.836  0.885  1.0
  Ca  Ca1  1  0.484  0.336  0.615  1.0
  Ca  Ca2  1  0.016  0.164  0.115  1.0
  Ca  Ca3  1  0.516  0.664  0.385  1.0
  P  P4  1  0.287  0.598  0.016  1.0
  P  P5  1  0.787  0.098  0.484  1.0
  P  P6  1  0.713  0.402  0.984  1.0
  P  P7  1  0.213  0.902  0.516  1.0
  P  P8  1  0.325  0.281  0.897  1.0
  P  P9  1  0.825  0.781  0.603  1.0
  P  P10  1  0.675  0.719  0.103  1.0
  P  P11  1  0.175  0.219  0.397  1.0
  O  O12  1  0.506  0.712  0.023  1.0
  O  O13  1  0.006  0.212  0.477  1.0
  O  O14  1  0.494  0.288  0.977  1.0
  O  O15  1  0.994  0.788  0.523  1.0
  O  O16  1  0.227  0.471  0.109  1.0
  O  O17  1  0.727  0.971  0.391  1.0
  O  O18  1  0.773  0.529  0.891  1.0
  O  O19  1  0.273  0.029  0.609  1.0
  O  O20  1  0.185  0.733  0.988  1.0
  O  O21  1  0.685  0.233  0.512  1.0
  O  O22  1  0.815  0.267  0.012  1.0
  O  O23  1  0.315  0.767  0.488  1.0
  O  O24  1  0.287  0.478  0.909  1.0
  O  O25  1  0.787  0.978  0.591  1.0
  O  O26  1  0.713  0.522  0.091  1.0
  O  O27  1  0.213  0.022  0.409  1.0
  O  O28  1  0.161  0.134  0.943  1.0
  O  O29  1  0.661  0.634  0.557  1.0
  O  O30  1  0.839  0.866  0.057  1.0
  O  O31  1  0.339  0.366  0.443  1.0
  O  O32  1  0.879  0.768  0.716  1.0
  O  O33  1  0.379  0.268  0.784  1.0
  O  O34  1  0.121  0.232  0.284  1.0
  O  O35  1  0.621  0.732  0.216  1.0
  O  O36  1  0.747  0.029  0.845  1.0
  O  O37  1  0.247  0.529  0.655  1.0
  O  O38  1  0.253  0.971  0.155  1.0
  O  O39  1  0.753  0.471  0.345  1.0
  O  O40  1  0.787  0.346  0.720  1.0
  O  O41  1  0.287  0.846  0.780  1.0
  O  O42  1  0.213  0.654  0.280  1.0
  O  O43  1  0.713  0.154  0.220  1.0
[/CIF]
.