The compound described by Be12Nb crystallizes in the tetragonal I4/mmm space group. There are three inequivalent Be sites. In the first Be site, Be(1) is bonded in a 12-coordinate geometry to two equivalent Be(1), four equivalent Be(2), four equivalent Be(3), and two equivalent Nb(1) atoms. In the second Be site, Be(2) is bonded in a 10-coordinate geometry to one Be(2), four equivalent Be(1), four equivalent Be(3), and one Nb(1) atom. In the third Be site, Be(3) is bonded to two equivalent Be(3), four equivalent Be(1), four equivalent Be(2), and two equivalent Nb(1) atoms to form a mixture of distorted edge, corner, and face-sharing BeBe10Nb2 cuboctahedra. Nb(1) is bonded in a 20-coordinate geometry to four equivalent Be(2), eight equivalent Be(1), and eight equivalent Be(3) atoms. is represented by the CIF file [CIF]
data_Be12Nb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.201
_cell_length_b   5.600
_cell_length_c   5.600
_cell_angle_alpha   81.884
_cell_angle_beta   67.941
_cell_angle_gamma   67.941
_symmetry_Int_Tables_number   1
_cell_volume   113.147
_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
  Be  Be0  1  0.500  0.782  0.218  1.0
  Be  Be1  1  0.351  0.648  0.648  1.0
  Be  Be2  1  0.000  0.353  0.647  1.0
  Be  Be3  1  0.000  0.647  0.353  1.0
  Be  Be4  1  0.718  0.783  0.783  1.0
  Be  Be5  1  0.500  0.000  0.500  1.0
  Be  Be6  1  0.500  0.218  0.782  1.0
  Be  Be7  1  0.649  0.352  0.352  1.0
  Be  Be8  1  0.282  0.217  0.217  1.0
  Be  Be9  1  0.500  0.500  0.000  1.0
  Be  Be10  1  0.000  0.500  0.000  1.0
  Be  Be11  1  0.000  0.000  0.500  1.0
  Nb  Nb12  1  0.000  0.000  0.000  1.0
[/CIF]
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The compound described by Be12Nb crystallizes in the tetragonal I4/mmm space group. There are three inequivalent Be sites. In the first Be site, Be(1) is bonded in a 12-coordinate geometry to two equivalent Be(1), four equivalent Be(2), four equivalent Be(3), and two equivalent Nb(1) atoms. In the second Be site, Be(2) is bonded in a 10-coordinate geometry to one Be(2), four equivalent Be(1), four equivalent Be(3), and one Nb(1) atom. In the third Be site, Be(3) is bonded to two equivalent Be(3), four equivalent Be(1), four equivalent Be(2), and two equivalent Nb(1) atoms to form a mixture of distorted edge, corner, and face-sharing BeBe10Nb2 cuboctahedra. Nb(1) is bonded in a 20-coordinate geometry to four equivalent Be(2), eight equivalent Be(1), and eight equivalent Be(3) atoms. is represented by the CIF file [CIF]
data_Be12Nb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.201
_cell_length_b   5.600
_cell_length_c   5.600
_cell_angle_alpha   81.884
_cell_angle_beta   67.941
_cell_angle_gamma   67.941
_symmetry_Int_Tables_number   1
_cell_volume   113.147
_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
  Be  Be0  1  0.500  0.782  0.218  1.0
  Be  Be1  1  0.351  0.648  0.648  1.0
  Be  Be2  1  0.000  0.353  0.647  1.0
  Be  Be3  1  0.000  0.647  0.353  1.0
  Be  Be4  1  0.718  0.783  0.783  1.0
  Be  Be5  1  0.500  0.000  0.500  1.0
  Be  Be6  1  0.500  0.218  0.782  1.0
  Be  Be7  1  0.649  0.352  0.352  1.0
  Be  Be8  1  0.282  0.217  0.217  1.0
  Be  Be9  1  0.500  0.500  0.000  1.0
  Be  Be10  1  0.000  0.500  0.000  1.0
  Be  Be11  1  0.000  0.000  0.500  1.0
  Nb  Nb12  1  0.000  0.000  0.000  1.0
[/CIF]
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