data_NpReSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.51
_cell_length_b   4.51
_cell_length_c   4.51
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NpReSi2
_chemical_formula_sum   'Np1 Re1 Si2'
_cell_volume   64.82
_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
  Np  Np0  1  0.19  0.19  0.19  1.0
  Re  Re1  1  0.0  0.0  0.0  1.0
  Si  Si2  1  0.59  0.59  0.59  1.0
  Si  Si3  1  0.78  0.78  0.78  1.0

data_NpReSi2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.51
_cell_length_b   4.51
_cell_length_c   11.04
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   NpReSi2
_chemical_formula_sum   'Np3 Re3 Si6'
_cell_volume   194.46
_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
  Np  Np0  3  0.0  0.0  0.81  1.0
  Re  Re1  3  0.0  0.0  0.0  1.0
  Si  Si2  3  0.0  0.0  0.22  1.0
  Si  Si3  3  0.0  0.0  0.41  1.0

Np Re Si Si
Np Re Si Si 0 1 o o o 0 3 - - o 0 3 - o - 0 3 o - - 0 2 - o o 0 2 o - o 0 2 o o - 1 3 - - - 1 2 - - o 1 2 - o - 1 2 o - - 2 3 o o o 
NpReSi2 crystallizes in the trigonal R3m space group. Np(1) is bonded in a 1-coordinate geometry to one Re(1), three equivalent Si(1), and three equivalent Si(2) atoms. The Np(1)-Re(1) bond length is 2.08 Å. All Np(1)-Si(1) bond lengths are 2.72 Å. All Np(1)-Si(2) bond lengths are 2.72 Å. Re(1) is bonded in a distorted single-bond geometry to one Np(1) and one Si(2) atom. The Re(1)-Si(2) bond length is 2.40 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to three equivalent Np(1) and one Si(2) atom to form distorted corner-sharing SiNp3Si tetrahedra. The Si(1)-Si(2) bond length is 2.08 Å. In the second Si site, Si(2) is bonded in a 5-coordinate geometry to three equivalent Np(1), one Re(1), and one Si(1) atom.