data_Mg2BeCr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.26
_cell_length_b   5.26
_cell_length_c   5.26
_cell_angle_alpha   148.64
_cell_angle_beta   129.69
_cell_angle_gamma   60.49
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2BeCr
_chemical_formula_sum   'Mg2 Be1 Cr1'
_cell_volume   57.87
_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  0.42  0.0  0.07  1.0
  Mg  Mg3  1  0.0  0.24  0.47  1.0
  Be  Be0  1  0.0  0.0  0.0  1.0
  Cr  Cr1  1  0.0  0.0  0.55  1.0

data_Mg2BeCr
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.84
_cell_length_b   4.47
_cell_length_c   5.26
_cell_angle_alpha   115.15
_cell_angle_beta   105.68
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2BeCr
_chemical_formula_sum   'Mg2 Be1 Cr1'
_cell_volume   57.87
_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  0.35  0.93  0.35  1.0
  Mg  Mg1  1  0.53  0.76  0.76  1.0
  Be  Be2  1  0.0  0.0  0.0  1.0
  Cr  Cr3  1  0.45  0.45  0.45  1.0

Mg Mg Be Cr
Mg2BeCr crystallizes in the triclinic P1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to one Be(1) and two equivalent Cr(1) atoms. The Mg(1)-Be(1) bond length is 2.00 Å. There is one shorter (2.18 Å) and one longer (2.40 Å) Mg(1)-Cr(1) bond length. In the second Mg site, Mg(2) is bonded in a 3-coordinate geometry to two equivalent Be(1) and one Cr(1) atom. There is one shorter (1.56 Å) and one longer (2.19 Å) Mg(2)-Be(1) bond length. The Mg(2)-Cr(1) bond length is 1.59 Å. Be(1) is bonded in a 4-coordinate geometry to one Mg(1), two equivalent Mg(2), and one Cr(1) atom. The Be(1)-Cr(1) bond length is 2.39 Å. Cr(1) is bonded in a 1-coordinate geometry to one Mg(2), two equivalent Mg(1), and one Be(1) atom.