The material structure described by Be3Ta crystallizes in the trigonal R-3m space group. There are three inequivalent Be sites. In the first Be site, Be(1) is bonded to one Be(3), two equivalent Be(2), four equivalent Be(1), two equivalent Ta(2), and three equivalent Ta(1) atoms to form distorted BeTa5Be7 cuboctahedra that share corners with two equivalent Be(3)Ta6Be6 cuboctahedra, corners with fifteen equivalent Be(1)Ta5Be7 cuboctahedra, edges with eight equivalent Be(1)Ta5Be7 cuboctahedra, faces with three equivalent Be(3)Ta6Be6 cuboctahedra, and faces with eleven equivalent Be(1)Ta5Be7 cuboctahedra. In the second Be site, Be(2) is bonded in a 9-coordinate geometry to six equivalent Be(1) and three equivalent Ta(2) atoms. In the third Be site, Be(3) is bonded to six equivalent Be(1) and six equivalent Ta(1) atoms to form BeTa6Be6 cuboctahedra that share corners with twelve equivalent Be(1)Ta5Be7 cuboctahedra, edges with six equivalent Be(3)Ta6Be6 cuboctahedra, and faces with eighteen equivalent Be(1)Ta5Be7 cuboctahedra. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 16-coordinate geometry to three equivalent Be(3), nine equivalent Be(1), one Ta(2), and three equivalent Ta(1) atoms. In the second Ta site, Ta(2) is bonded in a 20-coordinate geometry to six equivalent Be(2), twelve equivalent Be(1), and two equivalent Ta(1) atoms. is represented by the CIF card [CIF]
data_TaBe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.550
_cell_length_b   4.550
_cell_length_c   7.446
_cell_angle_alpha   72.211
_cell_angle_beta   72.211
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   124.898
_cell_formula_units_Z   3
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
  Ta  Ta0  1  0.140  0.140  0.580  1.0
  Ta  Ta1  1  0.860  0.860  0.420  1.0
  Ta  Ta2  1  0.000  0.000  0.000  1.0
  Be  Be3  1  0.075  0.584  0.757  1.0
  Be  Be4  1  0.584  0.584  0.757  1.0
  Be  Be5  1  0.584  0.075  0.757  1.0
  Be  Be6  1  0.925  0.416  0.243  1.0
  Be  Be7  1  0.416  0.416  0.243  1.0
  Be  Be8  1  0.416  0.925  0.243  1.0
  Be  Be9  1  0.334  0.334  0.997  1.0
  Be  Be10  1  0.666  0.666  0.003  1.0
  Be  Be11  1  0.500  0.500  0.500  1.0
[/CIF]
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The material structure described by Be3Ta crystallizes in the trigonal R-3m space group. There are three inequivalent Be sites. In the first Be site, Be(1) is bonded to one Be(3), two equivalent Be(2), four equivalent Be(1), two equivalent Ta(2), and three equivalent Ta(1) atoms to form distorted BeTa5Be7 cuboctahedra that share corners with two equivalent Be(3)Ta6Be6 cuboctahedra, corners with fifteen equivalent Be(1)Ta5Be7 cuboctahedra, edges with eight equivalent Be(1)Ta5Be7 cuboctahedra, faces with three equivalent Be(3)Ta6Be6 cuboctahedra, and faces with eleven equivalent Be(1)Ta5Be7 cuboctahedra. In the second Be site, Be(2) is bonded in a 9-coordinate geometry to six equivalent Be(1) and three equivalent Ta(2) atoms. In the third Be site, Be(3) is bonded to six equivalent Be(1) and six equivalent Ta(1) atoms to form BeTa6Be6 cuboctahedra that share corners with twelve equivalent Be(1)Ta5Be7 cuboctahedra, edges with six equivalent Be(3)Ta6Be6 cuboctahedra, and faces with eighteen equivalent Be(1)Ta5Be7 cuboctahedra. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 16-coordinate geometry to three equivalent Be(3), nine equivalent Be(1), one Ta(2), and three equivalent Ta(1) atoms. In the second Ta site, Ta(2) is bonded in a 20-coordinate geometry to six equivalent Be(2), twelve equivalent Be(1), and two equivalent Ta(1) atoms. is represented by the CIF card [CIF]
data_TaBe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.550
_cell_length_b   4.550
_cell_length_c   7.446
_cell_angle_alpha   72.211
_cell_angle_beta   72.211
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   124.898
_cell_formula_units_Z   3
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
  Ta  Ta0  1  0.140  0.140  0.580  1.0
  Ta  Ta1  1  0.860  0.860  0.420  1.0
  Ta  Ta2  1  0.000  0.000  0.000  1.0
  Be  Be3  1  0.075  0.584  0.757  1.0
  Be  Be4  1  0.584  0.584  0.757  1.0
  Be  Be5  1  0.584  0.075  0.757  1.0
  Be  Be6  1  0.925  0.416  0.243  1.0
  Be  Be7  1  0.416  0.416  0.243  1.0
  Be  Be8  1  0.416  0.925  0.243  1.0
  Be  Be9  1  0.334  0.334  0.997  1.0
  Be  Be10  1  0.666  0.666  0.003  1.0
  Be  Be11  1  0.500  0.500  0.500  1.0
[/CIF]
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