data_MgBeAu2
_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   MgBeAu2
_chemical_formula_sum   'Mg1 Be1 Au2'
_cell_volume   64.65
_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  Mg3  1  0.59  0.59  0.59  1.0
  Be  Be2  1  0.0  0.0  0.0  1.0
  Au  Au0  1  0.19  0.19  0.19  1.0
  Au  Au1  1  0.78  0.78  0.78  1.0

data_MgBeAu2
_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   MgBeAu2
_chemical_formula_sum   'Mg3 Be3 Au6'
_cell_volume   193.94
_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  0.41  1.0
  Be  Be1  3  0.0  0.0  0.0  1.0
  Au  Au2  3  0.0  0.0  0.22  1.0
  Au  Au3  3  0.0  0.0  0.81  1.0

Mg Be Au Au
MgBeAu2 crystallizes in the trigonal R3m space group. Mg(1) is bonded in a distorted single-bond geometry to one Au(2) and three equivalent Au(1) atoms. The Mg(1)-Au(2) bond length is 2.05 Å. All Mg(1)-Au(1) bond lengths are 2.73 Å. Be(1) is bonded in a distorted linear geometry to one Au(1) and one Au(2) atom. The Be(1)-Au(1) bond length is 2.05 Å. The Be(1)-Au(2) bond length is 2.45 Å. There are two inequivalent Au sites. In the first Au site, Au(1) is bonded to three equivalent Mg(1) and one Be(1) atom to form distorted corner-sharing AuMg3Be tetrahedra. In the second Au site, Au(2) is bonded in a distorted linear geometry to one Mg(1) and one Be(1) atom.