data_Mg3Be
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.62
_cell_length_b   5.62
_cell_length_c   5.62
_cell_angle_alpha   148.3
_cell_angle_beta   65.08
_cell_angle_gamma   124.79
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg3Be
_chemical_formula_sum   'Mg3 Be1'
_cell_volume   75.9
_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  Mg1  1  0.0  0.68  0.34  1.0
  Mg  Mg2  1  0.0  0.74  0.32  1.0
  Mg  Mg3  1  0.54  0.06  0.73  1.0
  Be  Be0  1  0.0  0.0  0.16  1.0

data_Mg3Be
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.07
_cell_length_b   5.21
_cell_length_c   5.62
_cell_angle_alpha   117.61
_cell_angle_beta   105.85
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg3Be
_chemical_formula_sum   'Mg3 Be1'
_cell_volume   75.9
_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  Mg0  1  0.53  0.33  0.8  1.0
  Mg  Mg1  1  0.68  0.34  0.34  1.0
  Mg  Mg2  1  0.74  0.42  0.42  1.0
  Be  Be3  1  0.0  0.84  0.84  1.0

Mg Mg Mg Be
Mg3Be crystallizes in the triclinic P1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a single-bond geometry to one Mg(2) and one Mg(3) atom. The Mg(1)-Mg(2) bond length is 0.41 Å. The Mg(1)-Mg(3) bond length is 2.96 Å. In the second Mg site, Mg(2) is bonded in a distorted single-bond geometry to one Mg(1), two equivalent Mg(3), and one Be(1) atom. There is one shorter (2.61 Å) and one longer (2.94 Å) Mg(2)-Mg(3) bond length. The Mg(2)-Be(1) bond length is 2.28 Å. In the third Mg site, Mg(3) is bonded in a 8-coordinate geometry to one Mg(1), two equivalent Mg(2), two equivalent Mg(3), and three equivalent Be(1) atoms. Both Mg(3)-Mg(3) bond lengths are 3.07 Å. There are a spread of Mg(3)-Be(1) bond distances ranging from 2.89-3.04 Å. Be(1) is bonded in a distorted single-bond geometry to one Mg(2) and three equivalent Mg(3) atoms.