data_CaHgP3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.03
_cell_length_b   5.03
_cell_length_c   5.03
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaHgP3
_chemical_formula_sum   'Ca1 Hg1 P3'
_cell_volume   127.22
_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
  Ca  Ca3  1  0.0  0.0  0.0  1.0
  Hg  Hg4  1  0.51  0.51  0.51  1.0
  P  P0  1  0.51  0.0  0.51  1.0
  P  P1  1  0.51  0.51  0.0  1.0
  P  P2  1  0.0  0.51  0.51  1.0

data_CaHgP3
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.11
_cell_length_b   7.11
_cell_length_c   8.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CaHgP3
_chemical_formula_sum   'Ca3 Hg3 P9'
_cell_volume   381.65
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.0  1.0
  Hg  Hg1  3  0.0  0.0  0.51  1.0
  P  P2  9  0.17  0.34  0.34  1.0

Ca Hg P P P
CaHgP3 is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Ca(1) is bonded in a 9-coordinate geometry to nine equivalent P(1) atoms. There are three shorter (3.45 Å) and six longer (3.56 Å) Ca(1)-P(1) bond lengths. Hg(1) is bonded to six equivalent P(1) atoms to form corner-sharing HgP6 octahedra. The corner-sharing octahedra are not tilted. There are three shorter (2.44 Å) and three longer (2.59 Å) Hg(1)-P(1) bond lengths. P(1) is bonded in a 2-coordinate geometry to three equivalent Ca(1) and two equivalent Hg(1) atoms.