data_MgCrAg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.5
_cell_length_b   4.5
_cell_length_c   4.5
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgCrAg
_chemical_formula_sum   'Mg1 Cr1 Ag1'
_cell_volume   64.48
_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
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Cr  Cr1  1  0.77  0.77  0.77  1.0
  Ag  Ag0  1  0.59  0.59  0.59  1.0

data_MgCrAg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.5
_cell_length_b   4.5
_cell_length_c   11.03
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   MgCrAg
_chemical_formula_sum   'Mg3 Cr3 Ag3'
_cell_volume   193.44
_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
  Mg  Mg0  3  0.0  0.0  0.0  1.0
  Cr  Cr1  3  0.0  0.0  0.23  1.0
  Ag  Ag2  3  0.0  0.0  0.41  1.0

Mg Cr Ag
Mg Cr Ag 0 1 - - - 0 1 - - o 0 1 o - - 0 1 - o - 0 2 - - o 0 2 - o - 0 2 o - - 1 2 o o o 
MgCrAg is half-Heusler structured and crystallizes in the trigonal R3m space group. Mg(1) is bonded in a 7-coordinate geometry to four equivalent Cr(1) and three equivalent Ag(1) atoms. There is one shorter (2.49 Å) and three longer (2.86 Å) Mg(1)-Cr(1) bond lengths. All Mg(1)-Ag(1) bond lengths are 2.73 Å. Cr(1) is bonded in a 8-coordinate geometry to four equivalent Mg(1) and four equivalent Ag(1) atoms. There is one shorter (2.01 Å) and three longer (3.08 Å) Cr(1)-Ag(1) bond lengths. Ag(1) is bonded in a 7-coordinate geometry to three equivalent Mg(1) and four equivalent Cr(1) atoms.