data_Sr3Ag
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.12
_cell_length_b   6.12
_cell_length_c   6.12
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sr3Ag
_chemical_formula_sum   'Sr3 Ag1'
_cell_volume   162.41
_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
  Sr  Sr1  1  0.5  0.5  0.5  1.0
  Sr  Sr2  1  0.0  0.0  0.0  1.0
  Sr  Sr3  1  0.17  0.17  0.17  1.0
  Ag  Ag0  1  0.33  0.33  0.33  1.0

data_Sr3Ag
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.12
_cell_length_b   6.12
_cell_length_c   15.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Sr3Ag
_chemical_formula_sum   'Sr9 Ag3'
_cell_volume   487.24
_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
  Sr  Sr0  3  0.0  0.0  0.0  1.0
  Sr  Sr1  3  0.0  0.0  0.5  1.0
  Sr  Sr2  3  0.0  0.0  0.83  1.0
  Ag  Ag3  3  0.0  0.0  0.67  1.0

Sr Sr Sr Ag
Sr3Ag crystallizes in the trigonal R3m space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a single-bond geometry to one Ag(1) atom. The Sr(1)-Ag(1) bond length is 2.48 Å. In the second Sr site, Sr(2) is bonded to one Sr(3) and three equivalent Ag(1) atoms to form SrSrAg3 trigonal pyramids that share  a cornercorner with one Ag(1)Sr5 trigonal bipyramid and corners with six equivalent Sr(2)SrAg3 trigonal pyramids. The Sr(2)-Sr(3) bond length is 2.48 Å. All Sr(2)-Ag(1) bond lengths are 3.54 Å. In the third Sr site, Sr(3) is bonded in a distorted single-bond geometry to one Sr(2) and one Ag(1) atom. The Sr(3)-Ag(1) bond length is 2.48 Å. Ag(1) is bonded to one Sr(1), one Sr(3), and three equivalent Sr(2) atoms to form distorted AgSr5 trigonal bipyramids that share corners with six equivalent Ag(1)Sr5 trigonal bipyramids and  a cornercorner with one Sr(2)SrAg3 trigonal pyramid.