The compound described by Y20Si12C crystallizes in the monoclinic P2/m space group. There are eight inequivalent Y sites. In the first Y site, Y(1) is bonded in a 6-coordinate geometry to two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms. In the second Y site, Y(2) is bonded in a 6-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and two equivalent Si(4) atoms. In the third Y site, Y(3) is bonded in a 6-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and two equivalent Si(4) atoms. In the fourth Y site, Y(4) is bonded in a 6-coordinate geometry to two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms. In the fifth Y site, Y(5) is bonded in a 5-coordinate geometry to two equivalent Si(4) and three equivalent Si(2) atoms. In the sixth Y site, Y(6) is bonded in a 1-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and one C(1) atom. In the seventh Y site, Y(7) is bonded in a 5-coordinate geometry to one Si(2), one Si(3), and three equivalent Si(4) atoms. In the eighth Y site, Y(8) is bonded in a 1-coordinate geometry to one Si(1), one Si(4), three equivalent Si(3), and one C(1) atom. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to two equivalent Y(2), two equivalent Y(3), two equivalent Y(6), and two equivalent Y(8) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Y(1), two equivalent Y(4), two equivalent Y(7), and three equivalent Y(5) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Y(1), one Y(2), one Y(3), one Y(4), one Y(6), one Y(7), and three equivalent Y(8) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Y(1), one Y(2), one Y(3), one Y(4), one Y(5), one Y(8), and three equivalent Y(7) atoms. C(1) is bonded in an octahedral geometry to two equivalent Y(6) and four equivalent Y(8) atoms. is represented by the CIF file [CIF]
data_Y20Si12C
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.636
_cell_length_b   6.429
_cell_length_c   8.452
_cell_angle_alpha   89.956
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   795.297
_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
  Y  Y0  1  0.663  0.500  0.500  1.0
  Y  Y1  1  0.171  0.500  0.000  1.0
  Y  Y2  1  0.829  0.500  0.000  1.0
  Y  Y3  1  0.337  0.500  0.500  1.0
  Y  Y4  1  0.838  0.000  0.000  1.0
  Y  Y5  1  0.329  0.000  0.500  1.0
  Y  Y6  1  0.671  0.000  0.500  1.0
  Y  Y7  1  0.162  0.000  0.000  1.0
  Y  Y8  1  0.500  0.246  0.756  1.0
  Y  Y9  1  0.000  0.274  0.265  1.0
  Y  Y10  1  0.621  0.248  0.121  1.0
  Y  Y11  1  0.118  0.272  0.618  1.0
  Y  Y12  1  0.882  0.272  0.618  1.0
  Y  Y13  1  0.379  0.248  0.121  1.0
  Y  Y14  1  0.000  0.726  0.735  1.0
  Y  Y15  1  0.500  0.754  0.244  1.0
  Y  Y16  1  0.882  0.728  0.382  1.0
  Y  Y17  1  0.379  0.752  0.879  1.0
  Y  Y18  1  0.621  0.752  0.879  1.0
  Y  Y19  1  0.118  0.728  0.382  1.0
  Si  Si20  1  0.000  0.263  0.899  1.0
  Si  Si21  1  0.500  0.242  0.395  1.0
  Si  Si22  1  0.800  0.256  0.301  1.0
  Si  Si23  1  0.303  0.246  0.803  1.0
  Si  Si24  1  0.697  0.246  0.803  1.0
  Si  Si25  1  0.200  0.256  0.301  1.0
  Si  Si26  1  0.500  0.758  0.605  1.0
  Si  Si27  1  0.000  0.737  0.101  1.0
  Si  Si28  1  0.697  0.754  0.197  1.0
  Si  Si29  1  0.200  0.744  0.699  1.0
  Si  Si30  1  0.800  0.744  0.699  1.0
  Si  Si31  1  0.303  0.754  0.197  1.0
  C  C32  1  0.000  0.500  0.500  1.0
[/CIF]
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The compound described by Y20Si12C crystallizes in the monoclinic P2/m space group. There are eight inequivalent Y sites. In the first Y site, Y(1) is bonded in a 6-coordinate geometry to two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms. In the second Y site, Y(2) is bonded in a 6-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and two equivalent Si(4) atoms. In the third Y site, Y(3) is bonded in a 6-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and two equivalent Si(4) atoms. In the fourth Y site, Y(4) is bonded in a 6-coordinate geometry to two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms. In the fifth Y site, Y(5) is bonded in a 5-coordinate geometry to two equivalent Si(4) and three equivalent Si(2) atoms. In the sixth Y site, Y(6) is bonded in a 1-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and one C(1) atom. In the seventh Y site, Y(7) is bonded in a 5-coordinate geometry to one Si(2), one Si(3), and three equivalent Si(4) atoms. In the eighth Y site, Y(8) is bonded in a 1-coordinate geometry to one Si(1), one Si(4), three equivalent Si(3), and one C(1) atom. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to two equivalent Y(2), two equivalent Y(3), two equivalent Y(6), and two equivalent Y(8) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Y(1), two equivalent Y(4), two equivalent Y(7), and three equivalent Y(5) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Y(1), one Y(2), one Y(3), one Y(4), one Y(6), one Y(7), and three equivalent Y(8) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Y(1), one Y(2), one Y(3), one Y(4), one Y(5), one Y(8), and three equivalent Y(7) atoms. C(1) is bonded in an octahedral geometry to two equivalent Y(6) and four equivalent Y(8) atoms. is represented by the CIF file [CIF]
data_Y20Si12C
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.636
_cell_length_b   6.429
_cell_length_c   8.452
_cell_angle_alpha   89.956
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   795.297
_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
  Y  Y0  1  0.663  0.500  0.500  1.0
  Y  Y1  1  0.171  0.500  0.000  1.0
  Y  Y2  1  0.829  0.500  0.000  1.0
  Y  Y3  1  0.337  0.500  0.500  1.0
  Y  Y4  1  0.838  0.000  0.000  1.0
  Y  Y5  1  0.329  0.000  0.500  1.0
  Y  Y6  1  0.671  0.000  0.500  1.0
  Y  Y7  1  0.162  0.000  0.000  1.0
  Y  Y8  1  0.500  0.246  0.756  1.0
  Y  Y9  1  0.000  0.274  0.265  1.0
  Y  Y10  1  0.621  0.248  0.121  1.0
  Y  Y11  1  0.118  0.272  0.618  1.0
  Y  Y12  1  0.882  0.272  0.618  1.0
  Y  Y13  1  0.379  0.248  0.121  1.0
  Y  Y14  1  0.000  0.726  0.735  1.0
  Y  Y15  1  0.500  0.754  0.244  1.0
  Y  Y16  1  0.882  0.728  0.382  1.0
  Y  Y17  1  0.379  0.752  0.879  1.0
  Y  Y18  1  0.621  0.752  0.879  1.0
  Y  Y19  1  0.118  0.728  0.382  1.0
  Si  Si20  1  0.000  0.263  0.899  1.0
  Si  Si21  1  0.500  0.242  0.395  1.0
  Si  Si22  1  0.800  0.256  0.301  1.0
  Si  Si23  1  0.303  0.246  0.803  1.0
  Si  Si24  1  0.697  0.246  0.803  1.0
  Si  Si25  1  0.200  0.256  0.301  1.0
  Si  Si26  1  0.500  0.758  0.605  1.0
  Si  Si27  1  0.000  0.737  0.101  1.0
  Si  Si28  1  0.697  0.754  0.197  1.0
  Si  Si29  1  0.200  0.744  0.699  1.0
  Si  Si30  1  0.800  0.744  0.699  1.0
  Si  Si31  1  0.303  0.754  0.197  1.0
  C  C32  1  0.000  0.500  0.500  1.0
[/CIF]
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