data_InSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.64
_cell_length_b   5.64
_cell_length_c   5.64
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   InSe3
_chemical_formula_sum   'In2 Se6'
_cell_volume   179.73
_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
  In  In0  1  0.82  0.82  0.82  1.0
  In  In1  1  0.0  0.0  0.0  1.0
  Se  Se2  1  0.41  0.0  0.82  1.0
  Se  Se3  1  0.23  0.0  0.82  1.0
  Se  Se4  1  0.82  0.41  0.0  1.0
  Se  Se5  1  0.82  0.23  0.0  1.0
  Se  Se6  1  0.0  0.82  0.23  1.0
  Se  Se7  1  0.0  0.82  0.41  1.0

data_InSe3
_symmetry_space_group_name_H-M   R3
_cell_length_a   7.98
_cell_length_b   7.98
_cell_length_c   9.77
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   InSe3
_chemical_formula_sum   'In6 Se18'
_cell_volume   539.2
_cell_formula_units_Z   6
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  'x+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+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
  In  In0  3  0.0  0.0  0.0  1.0
  In  In1  3  0.0  0.0  0.82  1.0
  Se  Se2  9  0.0  0.59  0.41  1.0
  Se  Se3  9  0.14  0.68  0.68  1.0

In In Se Se Se Se Se Se
In In Se Se Se Se Se Se 0 1 + + + 1 5 - o o 1 6 o - o 1 3 o o - 2 3 o o o 4 5 o o o 6 7 o o o 
InSe3 crystallizes in the trigonal R3 space group. There are two inequivalent In sites. In the first In site, In(1) is bonded in a distorted tetrahedral geometry to one In(2) and three equivalent Se(1) atoms. The In(1)-In(2) bond length is 1.74 Å. All In(1)-Se(1) bond lengths are 2.53 Å. In the second In site, In(2) is bonded in a distorted trigonal pyramidal geometry to one In(1) and three equivalent Se(2) atoms. All In(2)-Se(2) bond lengths are 1.65 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted bent 150 degrees geometry to one In(1) and one Se(2) atom. The Se(1)-Se(2) bond length is 1.01 Å. In the second Se site, Se(2) is bonded in a distorted single-bond geometry to one In(2) and one Se(1) atom.