data_AgSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.99
_cell_length_b   4.99
_cell_length_c   3.26
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   AgSe3
_chemical_formula_sum   'Ag1 Se3'
_cell_volume   81.26
_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
  Ag  Ag0  1  0.5  0.5  0.0  1.0
  Se  Se1  1  0.5  0.0  0.63  1.0
  Se  Se2  1  0.0  0.5  0.63  1.0
  Se  Se3  1  0.0  0.0  0.0  1.0

data_AgSe3
_symmetry_space_group_name_H-M   P4mm
_cell_length_a   4.99
_cell_length_b   4.99
_cell_length_c   3.26
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   99
_chemical_formula_structural   AgSe3
_chemical_formula_sum   'Ag1 Se3'
_cell_volume   81.26
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x, z'
  3  '-x, -y, z'
  4  'y, -x, z'
  5  '-x, y, z'
  6  'y, x, z'
  7  'x, -y, z'
  8  '-y, -x, 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
  Ag  Ag0  1  0.0  0.0  -0.0  1.0
  Se  Se1  2  0.0  0.5  0.63  1.0
  Se  Se2  1  0.5  0.5  0.0  1.0

Ag Se Se Se
Ag Se Se Se 0 2 o o - 0 2 o o o 0 2 + o - 0 2 + o o 0 1 o o - 0 1 o o o 0 1 o + - 0 1 o + o 0 0 o o + 1 3 o o o 1 3 o o + 1 3 + o o 1 3 + o + 1 1 o o + 2 3 o o o 2 3 o o + 2 3 o + o 2 3 o + + 2 2 o o + 3 3 o o + 
AgSe3 crystallizes in the monoclinic Cm space group. Ag(1) is bonded in a 4-coordinate geometry to eight equivalent Se(1) atoms. There are a spread of Ag(1)-Se(1) bond distances ranging from 2.76-3.24 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to four equivalent Ag(1) and two equivalent Se(2) atoms. There is one shorter (2.76 Å) and one longer (2.79 Å) Se(1)-Se(2) bond length. In the second Se site, Se(2) is bonded in a 4-coordinate geometry to four equivalent Se(1) atoms.