data_SiP3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.35
_cell_length_b   5.35
_cell_length_c   4.82
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiP3
_chemical_formula_sum   'Si2 P6'
_cell_volume   119.48
_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
  Si  Si6  1  0.67  0.54  0.62  1.0
  Si  Si7  1  0.0  0.09  0.21  1.0
  P  P0  1  0.19  0.78  0.62  1.0
  P  P1  1  0.81  0.78  0.62  1.0
  P  P2  1  0.0  0.71  0.62  1.0
  P  P3  1  0.48  0.86  0.21  1.0
  P  P4  1  0.87  0.86  0.21  1.0
  P  P5  1  0.67  0.92  0.21  1.0

data_SiP3
_symmetry_space_group_name_H-M   P-1
_cell_length_a   4.82
_cell_length_b   5.35
_cell_length_c   5.35
_cell_angle_alpha   120.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   SiP3
_chemical_formula_sum   'Si2 P6'
_cell_volume   119.48
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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
  Si  Si0  2  0.21  0.34  0.23  1.0
  P  P1  2  0.21  0.47  0.46  1.0
  P  P2  2  0.21  0.66  0.4  1.0
  P  P3  2  0.21  0.85  0.46  1.0

Si Si P P P P P P
SiP3 is Cubic alpha N2-like structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two SiP3 clusters. Si(1) is bonded in a distorted single-bond geometry to one P(2) and one P(3) atom. The Si(1)-P(2) bond length is 1.08 Å. The Si(1)-P(3) bond length is 1.51 Å. There are three inequivalent P sites. In the first P site, P(1) is bonded in a distorted single-bond geometry to one P(3) atom. The P(1)-P(3) bond length is 0.90 Å. In the second P site, P(2) is bonded in a distorted single-bond geometry to one Si(1) and one P(3) atom. The P(2)-P(3) bond length is 1.23 Å. In the third P site, P(3) is bonded in a 3-coordinate geometry to one Si(1), one P(1), and one P(2) atom.