data_SrSi2P
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.92
_cell_length_b   4.92
_cell_length_c   4.92
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrSi2P
_chemical_formula_sum   'Sr1 Si2 P1'
_cell_volume   84.26
_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
  Sr  Sr3  1  0.74  0.74  0.74  1.0
  Si  Si1  1  0.0  0.0  0.0  1.0
  Si  Si2  1  0.22  0.22  0.22  1.0
  P  P0  1  0.48  0.48  0.48  1.0

data_SrSi2P
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.92
_cell_length_b   4.92
_cell_length_c   12.05
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrSi2P
_chemical_formula_sum   'Sr3 Si6 P3'
_cell_volume   252.77
_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
  Sr  Sr0  3  0.0  0.0  0.26  1.0
  Si  Si1  3  0.0  0.0  0.0  1.0
  Si  Si2  3  0.0  0.0  0.78  1.0
  P  P3  3  0.0  0.0  0.52  1.0

Sr Si Si P
SrSi2P crystallizes in the trigonal R3m space group. Sr(1) is bonded in a 8-coordinate geometry to four equivalent Si(1), six equivalent Si(2), and four equivalent P(1) atoms. There are three shorter (2.97 Å) and one longer (3.14 Å) Sr(1)-Si(1) bond length. There are three shorter (3.34 Å) and three longer (3.63 Å) Sr(1)-Si(2) bond lengths. There are three shorter (2.97 Å) and one longer (3.14 Å) Sr(1)-P(1) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 5-coordinate geometry to four equivalent Sr(1) and one Si(2) atom. The Si(1)-Si(2) bond length is 2.64 Å. In the second Si site, Si(2) is bonded in a 10-coordinate geometry to six equivalent Sr(1), one Si(1), and three equivalent P(1) atoms. All Si(2)-P(1) bond lengths are 2.97 Å. P(1) is bonded to four equivalent Sr(1) and three equivalent Si(2) atoms to form a mixture of corner and edge-sharing PSr4Si3 tetrahedra.