data_Si3P5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.09
_cell_length_b   7.09
_cell_length_c   7.09
_cell_angle_alpha   102.69
_cell_angle_beta   102.69
_cell_angle_gamma   124.1
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si3P5
_chemical_formula_sum   'Si6 P10'
_cell_volume   260.76
_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  Si10  1  0.0  0.0  0.66  1.0
  Si  Si11  1  0.0  0.0  0.98  1.0
  Si  Si12  1  0.13  0.3  0.32  1.0
  Si  Si13  1  0.3  0.13  0.0  1.0
  Si  Si14  1  0.13  0.56  0.0  1.0
  Si  Si15  1  0.3  0.87  0.32  1.0
  P  P0  1  0.0  0.43  0.66  1.0
  P  P1  1  0.43  0.0  0.66  1.0
  P  P2  1  0.46  0.66  0.0  1.0
  P  P3  1  0.97  0.77  0.32  1.0
  P  P4  1  0.03  0.77  0.0  1.0
  P  P5  1  0.4  0.66  0.32  1.0
  P  P6  1  0.09  0.03  0.0  1.0
  P  P7  1  0.34  0.4  0.32  1.0
  P  P8  1  0.77  0.03  0.32  1.0
  P  P9  1  0.66  0.4  0.0  1.0

data_Si3P5
_symmetry_space_group_name_H-M   P1
_cell_length_a   6.65
_cell_length_b   7.09
_cell_length_c   7.09
_cell_angle_alpha   77.31
_cell_angle_beta   62.05
_cell_angle_gamma   62.05
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si3P5
_chemical_formula_sum   'Si6 P10'
_cell_volume   260.76
_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  Si0  1  0.0  0.0  0.02  1.0
  Si  Si1  1  0.0  0.0  0.34  1.0
  Si  Si2  1  0.13  0.16  0.0  1.0
  Si  Si3  1  0.3  0.84  0.68  1.0
  Si  Si4  1  0.56  0.57  0.0  1.0
  Si  Si5  1  0.87  0.43  0.68  1.0
  P  P6  1  0.0  0.43  0.34  1.0
  P  P7  1  0.03  0.06  0.0  1.0
  P  P8  1  0.03  0.74  0.68  1.0
  P  P9  1  0.4  0.26  0.0  1.0
  P  P10  1  0.4  0.94  0.68  1.0
  P  P11  1  0.43  0.57  0.34  1.0
  P  P12  1  0.66  0.74  0.68  1.0
  P  P13  1  0.66  0.8  -0.0  1.0
  P  P14  1  0.77  0.2  0.68  1.0
  P  P15  1  0.77  0.26  0.0  1.0

Si Si Si Si Si Si P P P P P P P P P P
Si3P5 crystallizes in the triclinic P1 space group. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded in a 5-coordinate geometry to one Si(2), one Si(4), one P(4), one P(7), and one P(9) atom. The Si(1)-Si(2) bond length is 2.29 Å. The Si(1)-Si(4) bond length is 2.37 Å. The Si(1)-P(4) bond length is 2.48 Å. The Si(1)-P(7) bond length is 2.28 Å. The Si(1)-P(9) bond length is 2.70 Å. In the second Si site, Si(2) is bonded in a single-bond geometry to one Si(1), one P(5), and one P(7) atom. The Si(2)-P(5) bond length is 1.76 Å. The Si(2)-P(7) bond length is 0.51 Å. In the third Si site, Si(3) is bonded in a 1-coordinate geometry to one P(8) and one P(9) atom. The Si(3)-P(8) bond length is 1.23 Å. The Si(3)-P(9) bond length is 2.18 Å. In the fourth Si site, Si(4) is bonded in a distorted single-bond geometry to one Si(1), one P(10), one P(5), and one P(7) atom. The Si(4)-P(10) bond length is 2.18 Å. The Si(4)-P(5) bond length is 2.18 Å. The Si(4)-P(7) bond length is 1.23 Å. In the fifth Si site, Si(5) is bonded in a 4-coordinate geometry to one P(1), one P(3), one P(5), and one P(6) atom. The Si(5)-P(1) bond length is 2.13 Å. The Si(5)-P(3) bond length is 1.99 Å. The Si(5)-P(5) bond length is 2.00 Å. The Si(5)-P(6) bond length is 2.30 Å. In the sixth Si site, Si(6) is bonded in a 4-coordinate geometry to one P(2), one P(4), one P(5), and one P(6) atom. The Si(6)-P(2) bond length is 2.13 Å. The Si(6)-P(4) bond length is 1.99 Å. The Si(6)-P(5) bond length is 2.30 Å. The Si(6)-P(6) bond length is 2.00 Å. There are ten inequivalent P sites. In the first P site, P(1) is bonded in a distorted single-bond geometry to one Si(5) atom. In the second P site, P(2) is bonded in a distorted single-bond geometry to one Si(6) atom. In the third P site, P(3) is bonded in a distorted single-bond geometry to one Si(5) atom. In the fourth P site, P(4) is bonded in a 2-coordinate geometry to one Si(1), one Si(6), and one P(5) atom. The P(4)-P(5) bond length is 2.41 Å. In the fifth P site, P(5) is bonded in a 7-coordinate geometry to one Si(2), one Si(4), one Si(5), one Si(6), one P(10), one P(4), and one P(7) atom. The P(5)-P(10) bond length is 2.45 Å. The P(5)-P(7) bond length is 1.62 Å. In the sixth P site, P(6) is bonded in a 3-coordinate geometry to one Si(5), one Si(6), and one P(8) atom. The P(6)-P(8) bond length is 1.62 Å. In the seventh P site, P(7) is bonded in a 2-coordinate geometry to one Si(1), one Si(2), one Si(4), and one P(5) atom. In the eighth P site, P(8) is bonded in a distorted single-bond geometry to one Si(3) and one P(6) atom. In the ninth P site, P(9) is bonded in a 1-coordinate geometry to one Si(1) and one Si(3) atom. In the tenth P site, P(10) is bonded in a distorted single-bond geometry to one Si(4) and one P(5) atom.