The compound described by Tc4Si7 crystallizes in the tetragonal P-4c2 space group. There are five inequivalent Tc sites. In the first Tc site, Tc(3) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms. In the second Tc site, Tc(4) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and four equivalent Si(2) atoms. In the third Tc site, Tc(5) is bonded in a 10-coordinate geometry to two equivalent Si(3), four equivalent Si(1), and four equivalent Si(2) atoms. In the fourth Tc site, Tc(1) is bonded in a 8-coordinate geometry to four equivalent Si(1) and four equivalent Si(4) atoms. In the fifth Tc site, Tc(2) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(2), and four equivalent Si(4) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Tc(1), one Tc(2), one Tc(3), one Tc(4), one Tc(5), one Si(1), one Si(2), one Si(3), and one Si(4) atom. In the second Si site, Si(2) is bonded in a 10-coordinate geometry to one Tc(2), one Tc(3), one Tc(5), two equivalent Tc(4), one Si(1), one Si(3), one Si(4), and two equivalent Si(2) atoms. In the third Si site, Si(3) is bonded in a 10-coordinate geometry to one Tc(5), two equivalent Tc(3), two equivalent Tc(4), one Si(3), two equivalent Si(1), and two equivalent Si(2) atoms. In the fourth Si site, Si(4) is bonded in a 5-coordinate geometry to one Tc(1), one Tc(3), two equivalent Tc(2), one Si(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_Si7Tc4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.742
_cell_length_b   5.742
_cell_length_c   18.035
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   594.652
_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
  Si  Si0  1  0.190  0.151  0.384  1.0
  Si  Si1  1  0.810  0.849  0.384  1.0
  Si  Si2  1  0.190  0.849  0.884  1.0
  Si  Si3  1  0.810  0.151  0.884  1.0
  Si  Si4  1  0.151  0.810  0.616  1.0
  Si  Si5  1  0.849  0.190  0.616  1.0
  Si  Si6  1  0.849  0.810  0.116  1.0
  Si  Si7  1  0.151  0.190  0.116  1.0
  Si  Si8  1  0.846  0.330  0.316  1.0
  Si  Si9  1  0.154  0.670  0.316  1.0
  Si  Si10  1  0.846  0.670  0.816  1.0
  Si  Si11  1  0.154  0.330  0.816  1.0
  Si  Si12  1  0.330  0.154  0.684  1.0
  Si  Si13  1  0.670  0.846  0.684  1.0
  Si  Si14  1  0.670  0.154  0.184  1.0
  Si  Si15  1  0.330  0.846  0.184  1.0
  Si  Si16  1  0.341  0.341  0.250  1.0
  Si  Si17  1  0.659  0.659  0.250  1.0
  Si  Si18  1  0.341  0.659  0.750  1.0
  Si  Si19  1  0.659  0.341  0.750  1.0
  Si  Si20  1  0.225  0.348  0.541  1.0
  Si  Si21  1  0.775  0.652  0.541  1.0
  Si  Si22  1  0.225  0.652  0.041  1.0
  Si  Si23  1  0.775  0.348  0.041  1.0
  Si  Si24  1  0.348  0.775  0.459  1.0
  Si  Si25  1  0.652  0.225  0.459  1.0
  Si  Si26  1  0.652  0.775  0.959  1.0
  Si  Si27  1  0.348  0.225  0.959  1.0
  Tc  Tc28  1  0.000  0.000  0.500  1.0
  Tc  Tc29  1  0.000  0.000  0.000  1.0
  Tc  Tc30  1  0.000  0.500  0.435  1.0
  Tc  Tc31  1  0.000  0.500  0.935  1.0
  Tc  Tc32  1  0.500  0.000  0.565  1.0
  Tc  Tc33  1  0.500  0.000  0.065  1.0
  Tc  Tc34  1  0.500  0.500  0.369  1.0
  Tc  Tc35  1  0.500  0.500  0.869  1.0
  Tc  Tc36  1  0.500  0.500  0.631  1.0
  Tc  Tc37  1  0.500  0.500  0.131  1.0
  Tc  Tc38  1  0.500  0.000  0.308  1.0
  Tc  Tc39  1  0.500  0.000  0.808  1.0
  Tc  Tc40  1  0.000  0.500  0.692  1.0
  Tc  Tc41  1  0.000  0.500  0.192  1.0
  Tc  Tc42  1  0.000  0.000  0.250  1.0
  Tc  Tc43  1  0.000  0.000  0.750  1.0
[/CIF]
.
The compound described by Tc4Si7 crystallizes in the tetragonal P-4c2 space group. There are five inequivalent Tc sites. In the first Tc site, Tc(3) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms. In the second Tc site, Tc(4) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and four equivalent Si(2) atoms. In the third Tc site, Tc(5) is bonded in a 10-coordinate geometry to two equivalent Si(3), four equivalent Si(1), and four equivalent Si(2) atoms. In the fourth Tc site, Tc(1) is bonded in a 8-coordinate geometry to four equivalent Si(1) and four equivalent Si(4) atoms. In the fifth Tc site, Tc(2) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(2), and four equivalent Si(4) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Tc(1), one Tc(2), one Tc(3), one Tc(4), one Tc(5), one Si(1), one Si(2), one Si(3), and one Si(4) atom. In the second Si site, Si(2) is bonded in a 10-coordinate geometry to one Tc(2), one Tc(3), one Tc(5), two equivalent Tc(4), one Si(1), one Si(3), one Si(4), and two equivalent Si(2) atoms. In the third Si site, Si(3) is bonded in a 10-coordinate geometry to one Tc(5), two equivalent Tc(3), two equivalent Tc(4), one Si(3), two equivalent Si(1), and two equivalent Si(2) atoms. In the fourth Si site, Si(4) is bonded in a 5-coordinate geometry to one Tc(1), one Tc(3), two equivalent Tc(2), one Si(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_Si7Tc4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.742
_cell_length_b   5.742
_cell_length_c   18.035
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   594.652
_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
  Si  Si0  1  0.190  0.151  0.384  1.0
  Si  Si1  1  0.810  0.849  0.384  1.0
  Si  Si2  1  0.190  0.849  0.884  1.0
  Si  Si3  1  0.810  0.151  0.884  1.0
  Si  Si4  1  0.151  0.810  0.616  1.0
  Si  Si5  1  0.849  0.190  0.616  1.0
  Si  Si6  1  0.849  0.810  0.116  1.0
  Si  Si7  1  0.151  0.190  0.116  1.0
  Si  Si8  1  0.846  0.330  0.316  1.0
  Si  Si9  1  0.154  0.670  0.316  1.0
  Si  Si10  1  0.846  0.670  0.816  1.0
  Si  Si11  1  0.154  0.330  0.816  1.0
  Si  Si12  1  0.330  0.154  0.684  1.0
  Si  Si13  1  0.670  0.846  0.684  1.0
  Si  Si14  1  0.670  0.154  0.184  1.0
  Si  Si15  1  0.330  0.846  0.184  1.0
  Si  Si16  1  0.341  0.341  0.250  1.0
  Si  Si17  1  0.659  0.659  0.250  1.0
  Si  Si18  1  0.341  0.659  0.750  1.0
  Si  Si19  1  0.659  0.341  0.750  1.0
  Si  Si20  1  0.225  0.348  0.541  1.0
  Si  Si21  1  0.775  0.652  0.541  1.0
  Si  Si22  1  0.225  0.652  0.041  1.0
  Si  Si23  1  0.775  0.348  0.041  1.0
  Si  Si24  1  0.348  0.775  0.459  1.0
  Si  Si25  1  0.652  0.225  0.459  1.0
  Si  Si26  1  0.652  0.775  0.959  1.0
  Si  Si27  1  0.348  0.225  0.959  1.0
  Tc  Tc28  1  0.000  0.000  0.500  1.0
  Tc  Tc29  1  0.000  0.000  0.000  1.0
  Tc  Tc30  1  0.000  0.500  0.435  1.0
  Tc  Tc31  1  0.000  0.500  0.935  1.0
  Tc  Tc32  1  0.500  0.000  0.565  1.0
  Tc  Tc33  1  0.500  0.000  0.065  1.0
  Tc  Tc34  1  0.500  0.500  0.369  1.0
  Tc  Tc35  1  0.500  0.500  0.869  1.0
  Tc  Tc36  1  0.500  0.500  0.631  1.0
  Tc  Tc37  1  0.500  0.500  0.131  1.0
  Tc  Tc38  1  0.500  0.000  0.308  1.0
  Tc  Tc39  1  0.500  0.000  0.808  1.0
  Tc  Tc40  1  0.000  0.500  0.692  1.0
  Tc  Tc41  1  0.000  0.500  0.192  1.0
  Tc  Tc42  1  0.000  0.000  0.250  1.0
  Tc  Tc43  1  0.000  0.000  0.750  1.0
[/CIF]
.