data_MgBe2Co
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.77
_cell_length_b   2.77
_cell_length_c   5.84
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgBe2Co
_chemical_formula_sum   'Mg1 Be2 Co1'
_cell_volume   44.74
_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  0.0  0.0  0.0  1.0
  Be  Be0  1  0.38  0.38  0.83  1.0
  Be  Be1  1  0.38  0.38  0.01  1.0
  Co  Co2  1  0.0  0.0  0.92  1.0

data_MgBe2Co
_symmetry_space_group_name_H-M   Cm
_cell_length_a   3.91
_cell_length_b   3.91
_cell_length_c   5.84
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgBe2Co
_chemical_formula_sum   'Mg2 Be4 Co2'
_cell_volume   89.48
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.0  1.0
  Be  Be1  2  0.38  0.0  0.01  1.0
  Be  Be2  2  0.38  0.0  0.83  1.0
  Co  Co3  2  0.0  0.0  0.92  1.0

Mg Be Be Co
Mg Be Be Co 0 3 o o - 1 2 o o + 
(Be)2MgCo crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Be clusters and two MgCo clusters. In each Be cluster, there are two inequivalent Be sites. In the first Be site, Be(1) is bonded in a 1-coordinate geometry to one Be(2) atom. The Be(1)-Be(2) bond length is 1.01 Å. In the second Be site, Be(2) is bonded in a distorted single-bond geometry to one Be(1) atom. In each MgCo cluster, Mg(1) is bonded in a single-bond geometry to one Co(1) atom. The Mg(1)-Co(1) bond length is 0.46 Å. Co(1) is bonded in a single-bond geometry to one Mg(1) atom.