data_YAgSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.03
_cell_length_b   5.03
_cell_length_c   5.03
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YAgSe3
_chemical_formula_sum   'Y1 Ag1 Se3'
_cell_volume   127.26
_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
  Y  Y0  1  0.0  0.0  0.0  1.0
  Ag  Ag4  1  0.51  0.51  0.51  1.0
  Se  Se1  1  0.51  0.0  0.51  1.0
  Se  Se2  1  0.51  0.51  0.0  1.0
  Se  Se3  1  0.0  0.51  0.51  1.0

data_YAgSe3
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.11
_cell_length_b   7.11
_cell_length_c   8.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   YAgSe3
_chemical_formula_sum   'Y3 Ag3 Se9'
_cell_volume   381.77
_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
  Y  Y0  3  0.0  0.0  0.0  1.0
  Ag  Ag1  3  0.0  0.0  0.51  1.0
  Se  Se2  9  0.17  0.34  0.34  1.0

Y Ag Se Se Se
Y Ag Se Se Se 0 1 - - - 0 3 - - o 0 3 - o o 0 3 o - o 0 3 o o o 0 2 - o - 0 2 - o o 0 2 o o - 0 2 o o o 0 4 o - - 0 4 o - o 0 4 o o - 0 4 o o o 1 4 o o o 1 4 + o o 1 2 o o o 1 2 o + o 1 3 o o o 1 3 o o + 
YAgSe3 is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Y(1) is bonded to twelve equivalent Se(1) atoms to form YSe12 cuboctahedra that share corners with twelve equivalent Y(1)Se12 cuboctahedra, faces with six equivalent Y(1)Se12 cuboctahedra, and faces with eight equivalent Ag(1)Se6 octahedra. There are a spread of Y(1)-Se(1) bond distances ranging from 3.45-3.66 Å. Ag(1) is bonded to six equivalent Se(1) atoms to form AgSe6 octahedra that share corners with six equivalent Ag(1)Se6 octahedra and faces with eight equivalent Y(1)Se12 cuboctahedra. The corner-sharing octahedra are not tilted. There are three shorter (2.44 Å) and three longer (2.59 Å) Ag(1)-Se(1) bond lengths. Se(1) is bonded to four equivalent Y(1) and two equivalent Ag(1) atoms to form a mixture of distorted edge, face, and corner-sharing SeY4Ag2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°.