The material described by TcAs3 is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. Tc(1) is bonded to four equivalent As(2) and eight equivalent As(1) atoms to form distorted TcAs12 cuboctahedra that share corners with four equivalent Tc(1)As12 cuboctahedra, corners with eight equivalent As(2)Tc4As8 cuboctahedra, edges with eight equivalent Tc(1)As12 cuboctahedra, faces with four equivalent Tc(1)As12 cuboctahedra, and faces with six equivalent As(2)Tc4As8 cuboctahedra. There are two inequivalent As sites. In the first As site, As(1) is bonded in a distorted body-centered cubic geometry to four equivalent Tc(1) and four equivalent As(2) atoms. In the second As site, As(2) is bonded to four equivalent Tc(1) and eight equivalent As(1) atoms to form AsTc4As8 cuboctahedra that share corners with four equivalent As(2)Tc4As8 cuboctahedra, corners with eight equivalent Tc(1)As12 cuboctahedra, edges with eight equivalent As(2)Tc4As8 cuboctahedra, faces with four equivalent As(2)Tc4As8 cuboctahedra, and faces with six equivalent Tc(1)As12 cuboctahedra. is represented by the CIF file [CIF]
data_TcAs3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.629
_cell_length_b   4.629
_cell_length_c   4.629
_cell_angle_alpha   123.244
_cell_angle_beta   123.244
_cell_angle_gamma   84.467
_symmetry_Int_Tables_number   1
_cell_volume   66.379
_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
  Tc  Tc0  1  0.000  0.000  0.000  1.0
  As  As1  1  0.750  0.250  0.500  1.0
  As  As2  1  0.250  0.750  0.500  1.0
  As  As3  1  0.500  0.500  0.000  1.0
[/CIF]
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The material described by TcAs3 is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. Tc(1) is bonded to four equivalent As(2) and eight equivalent As(1) atoms to form distorted TcAs12 cuboctahedra that share corners with four equivalent Tc(1)As12 cuboctahedra, corners with eight equivalent As(2)Tc4As8 cuboctahedra, edges with eight equivalent Tc(1)As12 cuboctahedra, faces with four equivalent Tc(1)As12 cuboctahedra, and faces with six equivalent As(2)Tc4As8 cuboctahedra. There are two inequivalent As sites. In the first As site, As(1) is bonded in a distorted body-centered cubic geometry to four equivalent Tc(1) and four equivalent As(2) atoms. In the second As site, As(2) is bonded to four equivalent Tc(1) and eight equivalent As(1) atoms to form AsTc4As8 cuboctahedra that share corners with four equivalent As(2)Tc4As8 cuboctahedra, corners with eight equivalent Tc(1)As12 cuboctahedra, edges with eight equivalent As(2)Tc4As8 cuboctahedra, faces with four equivalent As(2)Tc4As8 cuboctahedra, and faces with six equivalent Tc(1)As12 cuboctahedra. is represented by the CIF file [CIF]
data_TcAs3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.629
_cell_length_b   4.629
_cell_length_c   4.629
_cell_angle_alpha   123.244
_cell_angle_beta   123.244
_cell_angle_gamma   84.467
_symmetry_Int_Tables_number   1
_cell_volume   66.379
_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
  Tc  Tc0  1  0.000  0.000  0.000  1.0
  As  As1  1  0.750  0.250  0.500  1.0
  As  As2  1  0.250  0.750  0.500  1.0
  As  As3  1  0.500  0.500  0.000  1.0
[/CIF]
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