data_SrMgNbAg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.19
_cell_length_b   5.19
_cell_length_c   5.19
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrMgNbAg
_chemical_formula_sum   'Sr1 Mg1 Nb1 Ag1'
_cell_volume   98.72
_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  Sr3  1  0.83  0.83  0.83  1.0
  Mg  Mg1  1  0.0  0.0  0.0  1.0
  Nb  Nb2  1  0.5  0.5  0.5  1.0
  Ag  Ag0  1  0.67  0.67  0.67  1.0

data_SrMgNbAg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.19
_cell_length_b   5.19
_cell_length_c   12.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrMgNbAg
_chemical_formula_sum   'Sr3 Mg3 Nb3 Ag3'
_cell_volume   296.17
_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  0.17  1.0
  Mg  Mg1  3  0.0  0.0  1.0  1.0
  Nb  Nb2  3  0.0  0.0  0.5  1.0
  Ag  Ag3  3  0.0  0.0  0.33  1.0

Sr Mg Nb Ag
Sr Mg Nb Ag 0 3 o o o 0 1 + + + 2 3 o o o 
SrMgNbAg crystallizes in the trigonal R3m space group. Sr(1) is bonded in a 5-coordinate geometry to one Mg(1), three equivalent Nb(1), and one Ag(1) atom. The Sr(1)-Mg(1) bond length is 2.11 Å. All Sr(1)-Nb(1) bond lengths are 3.00 Å. The Sr(1)-Ag(1) bond length is 2.11 Å. Mg(1) is bonded to one Sr(1) and three equivalent Ag(1) atoms to form distorted MgSrAg3 trigonal pyramids that share corners with six equivalent Mg(1)SrAg3 trigonal pyramids and edges with three equivalent Nb(1)Sr3Ag trigonal pyramids. All Mg(1)-Ag(1) bond lengths are 3.00 Å. Nb(1) is bonded to three equivalent Sr(1) and one Ag(1) atom to form distorted NbSr3Ag trigonal pyramids that share corners with six equivalent Nb(1)Sr3Ag trigonal pyramids and edges with three equivalent Mg(1)SrAg3 trigonal pyramids. The Nb(1)-Ag(1) bond length is 2.11 Å. Ag(1) is bonded in a 5-coordinate geometry to one Sr(1), three equivalent Mg(1), and one Nb(1) atom.