data_SrMg2Be
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.09
_cell_length_b   5.09
_cell_length_c   5.09
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrMg2Be
_chemical_formula_sum   'Sr1 Mg2 Be1'
_cell_volume   93.02
_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  0.6  0.6  0.6  1.0
  Mg  Mg1  1  0.8  0.8  0.8  1.0
  Mg  Mg2  1  0.39  0.39  0.39  1.0
  Be  Be0  1  0.0  0.0  0.0  1.0

data_SrMg2Be
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.09
_cell_length_b   5.09
_cell_length_c   12.46
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrMg2Be
_chemical_formula_sum   'Sr3 Mg6 Be3'
_cell_volume   279.05
_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  0.4  1.0
  Mg  Mg1  3  0.0  0.0  0.2  1.0
  Mg  Mg2  3  0.0  0.0  0.61  1.0
  Be  Be3  3  0.0  0.0  0.0  1.0

Sr Mg Mg Be
Sr Mg Mg Be 0 2 o o o 0 2 o + o 0 2 + o o 0 2 o o + 0 3 o + + 0 3 + o + 0 3 + + o 0 1 o o o 1 2 o o + 1 2 o + o 1 2 + o o 1 3 + + + 1 3 + + o 1 3 o + + 1 3 + o + 2 3 o o + 2 3 o + o 2 3 + o o 
SrMg2Be crystallizes in the trigonal R3m space group. Sr(1) is bonded in a 11-coordinate geometry to four equivalent Mg(1), four equivalent Mg(2), and three equivalent Be(1) atoms. There is one shorter (2.52 Å) and three longer (3.36 Å) Sr(1)-Mg(1) bond lengths. There is one shorter (2.52 Å) and three longer (3.36 Å) Sr(1)-Mg(2) bond lengths. All Sr(1)-Be(1) bond lengths are 3.06 Å. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a linear geometry to four equivalent Sr(1) and one Be(1) atom. The Mg(1)-Be(1) bond length is 2.52 Å. In the second Mg site, Mg(2) is bonded in a distorted single-bond geometry to four equivalent Sr(1) and three equivalent Be(1) atoms. All Mg(2)-Be(1) bond lengths are 3.03 Å. Be(1) is bonded in a 7-coordinate geometry to three equivalent Sr(1), one Mg(1), and three equivalent Mg(2) atoms.