The material described by Hg3(PO4)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Hg sites. In the first Hg site, Hg(1) is bonded to one O(6), two equivalent O(3), and two equivalent O(5) atoms to form distorted HgO5 square pyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with two equivalent Hg(1)O5 square pyramids. In the second Hg site, Hg(2) is bonded in a distorted see-saw-like geometry to one O(1), one O(6), one O(7), and one O(8) atom. In the third Hg site, Hg(3) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(8), and two equivalent O(2) atoms. 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 Hg(1)O5 square pyramids. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Hg(1)O5 square pyramids. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a bent 120 degrees geometry to one Hg(3) and one P(1) atom. In the second O site, O(5) is bonded in a distorted single-bond geometry to two equivalent Hg(1) and one P(2) atom. In the third O site, O(6) is bonded in a 3-coordinate geometry to one Hg(1), one Hg(2), and one P(2) atom. In the fourth O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Hg(2) and one P(2) atom. In the fifth O site, O(8) is bonded in a 2-coordinate geometry to one Hg(2), one Hg(3), and one P(2) atom. In the sixth O site, O(1) is bonded in a distorted single-bond geometry to one Hg(2), one Hg(3), and one P(1) atom. In the seventh O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Hg(3) and one P(1) atom. In the eighth O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Hg(1) and one P(1) atom. is represented by the CIF file [CIF]
data_Hg3(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.538
_cell_length_b   6.447
_cell_length_c   9.810
_cell_angle_alpha   80.115
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   718.950
_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
  Hg  Hg0  1  0.166  0.082  0.656  1.0
  Hg  Hg1  1  0.666  0.418  0.344  1.0
  Hg  Hg2  1  0.834  0.918  0.344  1.0
  Hg  Hg3  1  0.334  0.582  0.656  1.0
  Hg  Hg4  1  0.892  0.673  0.699  1.0
  Hg  Hg5  1  0.392  0.827  0.301  1.0
  Hg  Hg6  1  0.108  0.327  0.301  1.0
  Hg  Hg7  1  0.608  0.173  0.699  1.0
  Hg  Hg8  1  0.120  0.825  0.039  1.0
  Hg  Hg9  1  0.620  0.675  0.961  1.0
  Hg  Hg10  1  0.880  0.175  0.961  1.0
  Hg  Hg11  1  0.380  0.325  0.039  1.0
  P  P12  1  0.367  0.904  0.896  1.0
  P  P13  1  0.867  0.596  0.104  1.0
  P  P14  1  0.633  0.096  0.104  1.0
  P  P15  1  0.133  0.404  0.896  1.0
  P  P16  1  0.898  0.192  0.612  1.0
  P  P17  1  0.398  0.308  0.388  1.0
  P  P18  1  0.102  0.808  0.388  1.0
  P  P19  1  0.602  0.692  0.612  1.0
  O  O20  1  0.440  0.100  0.861  1.0
  O  O21  1  0.940  0.400  0.139  1.0
  O  O22  1  0.560  0.900  0.139  1.0
  O  O23  1  0.060  0.600  0.861  1.0
  O  O24  1  0.439  0.698  0.916  1.0
  O  O25  1  0.939  0.802  0.084  1.0
  O  O26  1  0.561  0.302  0.084  1.0
  O  O27  1  0.061  0.198  0.916  1.0
  O  O28  1  0.280  0.871  0.780  1.0
  O  O29  1  0.780  0.629  0.220  1.0
  O  O30  1  0.720  0.129  0.220  1.0
  O  O31  1  0.220  0.371  0.780  1.0
  O  O32  1  0.297  0.917  0.030  1.0
  O  O33  1  0.797  0.583  0.970  1.0
  O  O34  1  0.703  0.083  0.970  1.0
  O  O35  1  0.203  0.417  0.030  1.0
  O  O36  1  0.810  0.181  0.498  1.0
  O  O37  1  0.310  0.319  0.502  1.0
  O  O38  1  0.190  0.819  0.502  1.0
  O  O39  1  0.690  0.681  0.498  1.0
  O  O40  1  0.479  0.746  0.551  1.0
  O  O41  1  0.979  0.754  0.449  1.0
  O  O42  1  0.521  0.254  0.449  1.0
  O  O43  1  0.021  0.246  0.551  1.0
  O  O44  1  0.595  0.487  0.720  1.0
  O  O45  1  0.095  0.013  0.280  1.0
  O  O46  1  0.405  0.513  0.280  1.0
  O  O47  1  0.905  0.987  0.720  1.0
  O  O48  1  0.642  0.855  0.703  1.0
  O  O49  1  0.142  0.645  0.297  1.0
  O  O50  1  0.358  0.145  0.297  1.0
  O  O51  1  0.858  0.355  0.703  1.0
[/CIF]
.
The material described by Hg3(PO4)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Hg sites. In the first Hg site, Hg(1) is bonded to one O(6), two equivalent O(3), and two equivalent O(5) atoms to form distorted HgO5 square pyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with two equivalent Hg(1)O5 square pyramids. In the second Hg site, Hg(2) is bonded in a distorted see-saw-like geometry to one O(1), one O(6), one O(7), and one O(8) atom. In the third Hg site, Hg(3) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(8), and two equivalent O(2) atoms. 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 Hg(1)O5 square pyramids. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Hg(1)O5 square pyramids. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a bent 120 degrees geometry to one Hg(3) and one P(1) atom. In the second O site, O(5) is bonded in a distorted single-bond geometry to two equivalent Hg(1) and one P(2) atom. In the third O site, O(6) is bonded in a 3-coordinate geometry to one Hg(1), one Hg(2), and one P(2) atom. In the fourth O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Hg(2) and one P(2) atom. In the fifth O site, O(8) is bonded in a 2-coordinate geometry to one Hg(2), one Hg(3), and one P(2) atom. In the sixth O site, O(1) is bonded in a distorted single-bond geometry to one Hg(2), one Hg(3), and one P(1) atom. In the seventh O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Hg(3) and one P(1) atom. In the eighth O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Hg(1) and one P(1) atom. is represented by the CIF file [CIF]
data_Hg3(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.538
_cell_length_b   6.447
_cell_length_c   9.810
_cell_angle_alpha   80.115
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   718.950
_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
  Hg  Hg0  1  0.166  0.082  0.656  1.0
  Hg  Hg1  1  0.666  0.418  0.344  1.0
  Hg  Hg2  1  0.834  0.918  0.344  1.0
  Hg  Hg3  1  0.334  0.582  0.656  1.0
  Hg  Hg4  1  0.892  0.673  0.699  1.0
  Hg  Hg5  1  0.392  0.827  0.301  1.0
  Hg  Hg6  1  0.108  0.327  0.301  1.0
  Hg  Hg7  1  0.608  0.173  0.699  1.0
  Hg  Hg8  1  0.120  0.825  0.039  1.0
  Hg  Hg9  1  0.620  0.675  0.961  1.0
  Hg  Hg10  1  0.880  0.175  0.961  1.0
  Hg  Hg11  1  0.380  0.325  0.039  1.0
  P  P12  1  0.367  0.904  0.896  1.0
  P  P13  1  0.867  0.596  0.104  1.0
  P  P14  1  0.633  0.096  0.104  1.0
  P  P15  1  0.133  0.404  0.896  1.0
  P  P16  1  0.898  0.192  0.612  1.0
  P  P17  1  0.398  0.308  0.388  1.0
  P  P18  1  0.102  0.808  0.388  1.0
  P  P19  1  0.602  0.692  0.612  1.0
  O  O20  1  0.440  0.100  0.861  1.0
  O  O21  1  0.940  0.400  0.139  1.0
  O  O22  1  0.560  0.900  0.139  1.0
  O  O23  1  0.060  0.600  0.861  1.0
  O  O24  1  0.439  0.698  0.916  1.0
  O  O25  1  0.939  0.802  0.084  1.0
  O  O26  1  0.561  0.302  0.084  1.0
  O  O27  1  0.061  0.198  0.916  1.0
  O  O28  1  0.280  0.871  0.780  1.0
  O  O29  1  0.780  0.629  0.220  1.0
  O  O30  1  0.720  0.129  0.220  1.0
  O  O31  1  0.220  0.371  0.780  1.0
  O  O32  1  0.297  0.917  0.030  1.0
  O  O33  1  0.797  0.583  0.970  1.0
  O  O34  1  0.703  0.083  0.970  1.0
  O  O35  1  0.203  0.417  0.030  1.0
  O  O36  1  0.810  0.181  0.498  1.0
  O  O37  1  0.310  0.319  0.502  1.0
  O  O38  1  0.190  0.819  0.502  1.0
  O  O39  1  0.690  0.681  0.498  1.0
  O  O40  1  0.479  0.746  0.551  1.0
  O  O41  1  0.979  0.754  0.449  1.0
  O  O42  1  0.521  0.254  0.449  1.0
  O  O43  1  0.021  0.246  0.551  1.0
  O  O44  1  0.595  0.487  0.720  1.0
  O  O45  1  0.095  0.013  0.280  1.0
  O  O46  1  0.405  0.513  0.280  1.0
  O  O47  1  0.905  0.987  0.720  1.0
  O  O48  1  0.642  0.855  0.703  1.0
  O  O49  1  0.142  0.645  0.297  1.0
  O  O50  1  0.358  0.145  0.297  1.0
  O  O51  1  0.858  0.355  0.703  1.0
[/CIF]
.