The structure described by Ta2Co crystallizes in the hexagonal P6_3/mcm space group. There are five inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to six Ta(2,2,2,2) and six equivalent Co(1) atoms to form TaTa6Co6 cuboctahedra that share corners with eighteen equivalent Co(1)Ta9Co3 cuboctahedra; edges with six equivalent Ta(1)Ta6Co6 cuboctahedra; edges with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra; faces with two equivalent Ta(1)Ta6Co6 cuboctahedra; faces with six equivalent Co(1)Ta9Co3 cuboctahedra; and faces with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra. In the second Ta site, Ta(2) is bonded to two equivalent Ta(1), six equivalent Ta(2), and four equivalent Co(1) atoms to form distorted TaTa8Co4 cuboctahedra that share corners with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; edges with four equivalent Ta(1)Ta6Co6 cuboctahedra; edges with eight equivalent Co(1)Ta9Co3 cuboctahedra; edges with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; faces with four equivalent Ta(1)Ta6Co6 cuboctahedra; faces with six equivalent Ta(2)Ta8Co4 cuboctahedra; and faces with eight equivalent Co(1)Ta9Co3 cuboctahedra. In the third Ta site, Ta(2) is bonded to two equivalent Ta(1); six Ta(2,2); and four equivalent Co(1) atoms to form distorted TaTa8Co4 cuboctahedra that share corners with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra; edges with four equivalent Ta(1)Ta6Co6 cuboctahedra; edges with eight equivalent Co(1)Ta9Co3 cuboctahedra; edges with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; faces with four equivalent Ta(1)Ta6Co6 cuboctahedra; faces with six Ta(2,2)Ta8Co4 cuboctahedra; and faces with eight equivalent Co(1)Ta9Co3 cuboctahedra. In the fourth Ta site, Ta(2) is bonded to two equivalent Ta(1), six equivalent Ta(2), and four equivalent Co(1) atoms to form distorted TaTa8Co4 cuboctahedra that share corners with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; edges with four equivalent Ta(1)Ta6Co6 cuboctahedra; edges with eight equivalent Co(1)Ta9Co3 cuboctahedra; edges with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; faces with four equivalent Ta(1)Ta6Co6 cuboctahedra; faces with six equivalent Ta(2)Ta8Co4 cuboctahedra; and faces with eight equivalent Co(1)Ta9Co3 cuboctahedra. In the fifth Ta site, Ta(2) is bonded to two equivalent Ta(1); six Ta(2,2); and four equivalent Co(1) atoms to form distorted TaTa8Co4 cuboctahedra that share corners with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra; edges with four equivalent Ta(1)Ta6Co6 cuboctahedra; edges with eight equivalent Co(1)Ta9Co3 cuboctahedra; edges with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; faces with four equivalent Ta(1)Ta6Co6 cuboctahedra; faces with six Ta(2,2)Ta8Co4 cuboctahedra; and faces with eight equivalent Co(1)Ta9Co3 cuboctahedra. Co(1) is bonded to three equivalent Ta(1); six Ta(2,2,2,2); and three equivalent Co(1) atoms to form distorted CoTa9Co3 cuboctahedra that share corners with nine equivalent Ta(1)Ta6Co6 cuboctahedra; corners with nine equivalent Co(1)Ta9Co3 cuboctahedra; edges with six equivalent Co(1)Ta9Co3 cuboctahedra; edges with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra; faces with three equivalent Ta(1)Ta6Co6 cuboctahedra; faces with five equivalent Co(1)Ta9Co3 cuboctahedra; and faces with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ta2Co
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.967
_cell_length_b   4.967
_cell_length_c   9.000
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   192.320
_cell_formula_units_Z   4
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  0.000  0.000  0.500  1.0
  Ta  Ta1  1  0.000  0.000  0.000  1.0
  Ta  Ta2  1  0.652  0.652  0.750  1.0
  Ta  Ta3  1  0.348  0.000  0.750  1.0
  Ta  Ta4  1  0.000  0.348  0.750  1.0
  Ta  Ta5  1  0.348  0.348  0.250  1.0
  Ta  Ta6  1  0.652  0.000  0.250  1.0
  Ta  Ta7  1  0.000  0.652  0.250  1.0
  Co  Co8  1  0.667  0.333  0.500  1.0
  Co  Co9  1  0.333  0.667  0.500  1.0
  Co  Co10  1  0.333  0.667  0.000  1.0
  Co  Co11  1  0.667  0.333  0.000  1.0
[/CIF]
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The structure described by Ta2Co crystallizes in the hexagonal P6_3/mcm space group. There are five inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to six Ta(2,2,2,2) and six equivalent Co(1) atoms to form TaTa6Co6 cuboctahedra that share corners with eighteen equivalent Co(1)Ta9Co3 cuboctahedra; edges with six equivalent Ta(1)Ta6Co6 cuboctahedra; edges with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra; faces with two equivalent Ta(1)Ta6Co6 cuboctahedra; faces with six equivalent Co(1)Ta9Co3 cuboctahedra; and faces with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra. In the second Ta site, Ta(2) is bonded to two equivalent Ta(1), six equivalent Ta(2), and four equivalent Co(1) atoms to form distorted TaTa8Co4 cuboctahedra that share corners with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; edges with four equivalent Ta(1)Ta6Co6 cuboctahedra; edges with eight equivalent Co(1)Ta9Co3 cuboctahedra; edges with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; faces with four equivalent Ta(1)Ta6Co6 cuboctahedra; faces with six equivalent Ta(2)Ta8Co4 cuboctahedra; and faces with eight equivalent Co(1)Ta9Co3 cuboctahedra. In the third Ta site, Ta(2) is bonded to two equivalent Ta(1); six Ta(2,2); and four equivalent Co(1) atoms to form distorted TaTa8Co4 cuboctahedra that share corners with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra; edges with four equivalent Ta(1)Ta6Co6 cuboctahedra; edges with eight equivalent Co(1)Ta9Co3 cuboctahedra; edges with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; faces with four equivalent Ta(1)Ta6Co6 cuboctahedra; faces with six Ta(2,2)Ta8Co4 cuboctahedra; and faces with eight equivalent Co(1)Ta9Co3 cuboctahedra. In the fourth Ta site, Ta(2) is bonded to two equivalent Ta(1), six equivalent Ta(2), and four equivalent Co(1) atoms to form distorted TaTa8Co4 cuboctahedra that share corners with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; edges with four equivalent Ta(1)Ta6Co6 cuboctahedra; edges with eight equivalent Co(1)Ta9Co3 cuboctahedra; edges with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; faces with four equivalent Ta(1)Ta6Co6 cuboctahedra; faces with six equivalent Ta(2)Ta8Co4 cuboctahedra; and faces with eight equivalent Co(1)Ta9Co3 cuboctahedra. In the fifth Ta site, Ta(2) is bonded to two equivalent Ta(1); six Ta(2,2); and four equivalent Co(1) atoms to form distorted TaTa8Co4 cuboctahedra that share corners with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra; edges with four equivalent Ta(1)Ta6Co6 cuboctahedra; edges with eight equivalent Co(1)Ta9Co3 cuboctahedra; edges with twelve Ta(2,2,2)Ta8Co4 cuboctahedra; faces with four equivalent Ta(1)Ta6Co6 cuboctahedra; faces with six Ta(2,2)Ta8Co4 cuboctahedra; and faces with eight equivalent Co(1)Ta9Co3 cuboctahedra. Co(1) is bonded to three equivalent Ta(1); six Ta(2,2,2,2); and three equivalent Co(1) atoms to form distorted CoTa9Co3 cuboctahedra that share corners with nine equivalent Ta(1)Ta6Co6 cuboctahedra; corners with nine equivalent Co(1)Ta9Co3 cuboctahedra; edges with six equivalent Co(1)Ta9Co3 cuboctahedra; edges with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra; faces with three equivalent Ta(1)Ta6Co6 cuboctahedra; faces with five equivalent Co(1)Ta9Co3 cuboctahedra; and faces with twelve Ta(2,2,2,2)Ta8Co4 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ta2Co
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.967
_cell_length_b   4.967
_cell_length_c   9.000
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   192.320
_cell_formula_units_Z   4
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  0.000  0.000  0.500  1.0
  Ta  Ta1  1  0.000  0.000  0.000  1.0
  Ta  Ta2  1  0.652  0.652  0.750  1.0
  Ta  Ta3  1  0.348  0.000  0.750  1.0
  Ta  Ta4  1  0.000  0.348  0.750  1.0
  Ta  Ta5  1  0.348  0.348  0.250  1.0
  Ta  Ta6  1  0.652  0.000  0.250  1.0
  Ta  Ta7  1  0.000  0.652  0.250  1.0
  Co  Co8  1  0.667  0.333  0.500  1.0
  Co  Co9  1  0.333  0.667  0.500  1.0
  Co  Co10  1  0.333  0.667  0.000  1.0
  Co  Co11  1  0.667  0.333  0.000  1.0
[/CIF]
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