The structure described by Tl4Si5O12 crystallizes in the monoclinic C2/c space group. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a distorted T-shaped geometry to one O(3) and two equivalent O(6) atoms. In the second Tl site, Tl(2) is bonded in a distorted T-shaped geometry to one O(6) and two equivalent O(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Tl(1), two equivalent Tl(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Tl(2), two equivalent Tl(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_Tl4Si5O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.436
_cell_length_b   7.436
_cell_length_c   13.189
_cell_angle_alpha   87.109
_cell_angle_beta   87.109
_cell_angle_gamma   103.301
_symmetry_Int_Tables_number   1
_cell_volume   707.325
_cell_formula_units_Z   2
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
  Tl  Tl0  1  0.073  0.132  0.624  1.0
  Tl  Tl1  1  0.868  0.927  0.876  1.0
  Tl  Tl2  1  0.927  0.868  0.376  1.0
  Tl  Tl3  1  0.132  0.073  0.124  1.0
  Tl  Tl4  1  0.035  0.630  0.631  1.0
  Tl  Tl5  1  0.370  0.965  0.869  1.0
  Tl  Tl6  1  0.965  0.370  0.369  1.0
  Tl  Tl7  1  0.630  0.035  0.131  1.0
  Si  Si8  1  0.639  0.248  0.581  1.0
  Si  Si9  1  0.752  0.361  0.919  1.0
  Si  Si10  1  0.361  0.752  0.419  1.0
  Si  Si11  1  0.248  0.639  0.081  1.0
  Si  Si12  1  0.381  0.166  0.397  1.0
  Si  Si13  1  0.834  0.619  0.103  1.0
  Si  Si14  1  0.619  0.834  0.603  1.0
  Si  Si15  1  0.166  0.381  0.897  1.0
  Si  Si16  1  0.510  0.490  0.750  1.0
  Si  Si17  1  0.490  0.510  0.250  1.0
  O  O18  1  0.537  0.362  0.658  1.0
  O  O19  1  0.638  0.463  0.842  1.0
  O  O20  1  0.463  0.638  0.342  1.0
  O  O21  1  0.362  0.537  0.158  1.0
  O  O22  1  0.566  0.705  0.709  1.0
  O  O23  1  0.295  0.434  0.791  1.0
  O  O24  1  0.434  0.295  0.291  1.0
  O  O25  1  0.705  0.566  0.209  1.0
  O  O26  1  0.857  0.332  0.563  1.0
  O  O27  1  0.668  0.143  0.937  1.0
  O  O28  1  0.143  0.668  0.437  1.0
  O  O29  1  0.332  0.857  0.063  1.0
  O  O30  1  0.539  0.249  0.474  1.0
  O  O31  1  0.751  0.461  0.026  1.0
  O  O32  1  0.461  0.751  0.526  1.0
  O  O33  1  0.249  0.539  0.974  1.0
  O  O34  1  0.591  0.037  0.633  1.0
  O  O35  1  0.963  0.409  0.867  1.0
  O  O36  1  0.409  0.963  0.367  1.0
  O  O37  1  0.037  0.591  0.133  1.0
  O  O38  1  0.175  0.156  0.441  1.0
  O  O39  1  0.844  0.825  0.059  1.0
  O  O40  1  0.825  0.844  0.559  1.0
  O  O41  1  0.156  0.175  0.941  1.0
[/CIF]
.
The structure described by Tl4Si5O12 crystallizes in the monoclinic C2/c space group. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a distorted T-shaped geometry to one O(3) and two equivalent O(6) atoms. In the second Tl site, Tl(2) is bonded in a distorted T-shaped geometry to one O(6) and two equivalent O(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Tl(1), two equivalent Tl(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Tl(2), two equivalent Tl(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_Tl4Si5O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.436
_cell_length_b   7.436
_cell_length_c   13.189
_cell_angle_alpha   87.109
_cell_angle_beta   87.109
_cell_angle_gamma   103.301
_symmetry_Int_Tables_number   1
_cell_volume   707.325
_cell_formula_units_Z   2
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
  Tl  Tl0  1  0.073  0.132  0.624  1.0
  Tl  Tl1  1  0.868  0.927  0.876  1.0
  Tl  Tl2  1  0.927  0.868  0.376  1.0
  Tl  Tl3  1  0.132  0.073  0.124  1.0
  Tl  Tl4  1  0.035  0.630  0.631  1.0
  Tl  Tl5  1  0.370  0.965  0.869  1.0
  Tl  Tl6  1  0.965  0.370  0.369  1.0
  Tl  Tl7  1  0.630  0.035  0.131  1.0
  Si  Si8  1  0.639  0.248  0.581  1.0
  Si  Si9  1  0.752  0.361  0.919  1.0
  Si  Si10  1  0.361  0.752  0.419  1.0
  Si  Si11  1  0.248  0.639  0.081  1.0
  Si  Si12  1  0.381  0.166  0.397  1.0
  Si  Si13  1  0.834  0.619  0.103  1.0
  Si  Si14  1  0.619  0.834  0.603  1.0
  Si  Si15  1  0.166  0.381  0.897  1.0
  Si  Si16  1  0.510  0.490  0.750  1.0
  Si  Si17  1  0.490  0.510  0.250  1.0
  O  O18  1  0.537  0.362  0.658  1.0
  O  O19  1  0.638  0.463  0.842  1.0
  O  O20  1  0.463  0.638  0.342  1.0
  O  O21  1  0.362  0.537  0.158  1.0
  O  O22  1  0.566  0.705  0.709  1.0
  O  O23  1  0.295  0.434  0.791  1.0
  O  O24  1  0.434  0.295  0.291  1.0
  O  O25  1  0.705  0.566  0.209  1.0
  O  O26  1  0.857  0.332  0.563  1.0
  O  O27  1  0.668  0.143  0.937  1.0
  O  O28  1  0.143  0.668  0.437  1.0
  O  O29  1  0.332  0.857  0.063  1.0
  O  O30  1  0.539  0.249  0.474  1.0
  O  O31  1  0.751  0.461  0.026  1.0
  O  O32  1  0.461  0.751  0.526  1.0
  O  O33  1  0.249  0.539  0.974  1.0
  O  O34  1  0.591  0.037  0.633  1.0
  O  O35  1  0.963  0.409  0.867  1.0
  O  O36  1  0.409  0.963  0.367  1.0
  O  O37  1  0.037  0.591  0.133  1.0
  O  O38  1  0.175  0.156  0.441  1.0
  O  O39  1  0.844  0.825  0.059  1.0
  O  O40  1  0.825  0.844  0.559  1.0
  O  O41  1  0.156  0.175  0.941  1.0
[/CIF]
.