data_MoAsSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.89
_cell_length_b   4.75
_cell_length_c   4.49
_cell_angle_alpha   90.0
_cell_angle_beta   105.7
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MoAsSe2
_chemical_formula_sum   'Mo1 As1 Se2'
_cell_volume   79.69
_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
  Mo  Mo1  1  0.42  0.37  0.22  1.0
  As  As0  1  0.64  0.0  0.98  1.0
  Se  Se2  1  0.51  0.0  0.29  1.0
  Se  Se3  1  0.33  0.37  0.98  1.0

data_MoAsSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.89
_cell_length_b   4.49
_cell_length_c   4.75
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   105.7
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MoAsSe2
_chemical_formula_sum   'Mo1 As1 Se2'
_cell_volume   79.69
_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
  Mo  Mo0  1  0.58  0.78  0.63  1.0
  As  As1  1  0.36  0.02  0.0  1.0
  Se  Se2  1  0.49  0.71  0.0  1.0
  Se  Se3  1  0.67  0.02  0.63  1.0

Mo As Se Se
Mo As Se Se 0 3 o o - 0 2 o o o 1 2 o o + 
MoAsSe2 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one MoAsSe2 cluster. Mo(1) is bonded in a 1-coordinate geometry to one Se(1) and one Se(2) atom. The Mo(1)-Se(1) bond length is 1.82 Å. The Mo(1)-Se(2) bond length is 1.07 Å. As(1) is bonded in a 1-coordinate geometry to one Se(1) atom. The As(1)-Se(1) bond length is 1.60 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted L-shaped geometry to one Mo(1) and one As(1) atom. In the second Se site, Se(2) is bonded in a distorted single-bond geometry to one Mo(1) atom.