The structure described by Si12CO24 is Low Tridymite-derived structured and crystallizes in the monoclinic Cm space group. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(13), one O(2), and one O(9) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(10), one O(14), and one O(2) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(12), one O(5), one O(6), and one O(9) atom to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(10), one O(11), one O(5), and one O(6) atom to form corner-sharing SiO4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(3), one O(7), and two equivalent O(13) atoms to form corner-sharing SiO4 tetrahedra. In the sixth Si site, Si(6) is bonded to one O(4), one O(8), and two equivalent O(14) atoms to form corner-sharing SiO4 tetrahedra. In the seventh Si site, Si(7) is bonded to one O(3), one O(7), and two equivalent O(11) atoms to form corner-sharing SiO4 tetrahedra. In the eighth Si site, Si(8) is bonded to one O(4), one O(8), and two equivalent O(12) atoms to form corner-sharing SiO4 tetrahedra. C(1) is bonded in a single-bond geometry to one O(3) atom. There are fourteen 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(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Si(5), one Si(7), and one C(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(8) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(7) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(8) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Si(4) and one Si(7) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(8) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(5) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(6) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Si12CO24
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.285
_cell_length_b   11.285
_cell_length_c   5.128
_cell_angle_alpha   89.821
_cell_angle_beta   89.821
_cell_angle_gamma   77.915
_symmetry_Int_Tables_number   1
_cell_volume   638.602
_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
  Si  Si0  1  0.655  0.247  0.948  1.0
  Si  Si1  1  0.247  0.655  0.948  1.0
  Si  Si2  1  0.345  0.752  0.447  1.0
  Si  Si3  1  0.752  0.345  0.447  1.0
  Si  Si4  1  0.585  0.993  0.027  1.0
  Si  Si5  1  0.993  0.585  0.027  1.0
  Si  Si6  1  0.419  0.003  0.529  1.0
  Si  Si7  1  0.003  0.419  0.529  1.0
  Si  Si8  1  0.377  0.377  0.913  1.0
  Si  Si9  1  0.623  0.623  0.424  1.0
  Si  Si10  1  0.269  0.269  0.433  1.0
  Si  Si11  1  0.727  0.727  0.923  1.0
  C  C12  1  0.208  0.208  0.000  1.0
  O  O13  1  0.745  0.294  0.152  1.0
  O  O14  1  0.294  0.745  0.152  1.0
  O  O15  1  0.254  0.705  0.652  1.0
  O  O16  1  0.705  0.254  0.652  1.0
  O  O17  1  0.302  0.302  0.121  1.0
  O  O18  1  0.695  0.695  0.625  1.0
  O  O19  1  0.476  0.008  0.817  1.0
  O  O20  1  0.008  0.476  0.817  1.0
  O  O21  1  0.529  0.985  0.317  1.0
  O  O22  1  0.985  0.529  0.317  1.0
  O  O23  1  0.346  0.346  0.616  1.0
  O  O24  1  0.654  0.654  0.125  1.0
  O  O25  1  0.651  0.108  0.014  1.0
  O  O26  1  0.108  0.651  0.014  1.0
  O  O27  1  0.350  0.890  0.512  1.0
  O  O28  1  0.890  0.350  0.512  1.0
  O  O29  1  0.321  0.127  0.479  1.0
  O  O30  1  0.127  0.321  0.479  1.0
  O  O31  1  0.687  0.872  0.969  1.0
  O  O32  1  0.872  0.687  0.969  1.0
  O  O33  1  0.520  0.335  0.973  1.0
  O  O34  1  0.335  0.520  0.973  1.0
  O  O35  1  0.478  0.663  0.473  1.0
  O  O36  1  0.663  0.478  0.473  1.0
[/CIF]
.
The structure described by Si12CO24 is Low Tridymite-derived structured and crystallizes in the monoclinic Cm space group. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(13), one O(2), and one O(9) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(10), one O(14), and one O(2) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(12), one O(5), one O(6), and one O(9) atom to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(10), one O(11), one O(5), and one O(6) atom to form corner-sharing SiO4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(3), one O(7), and two equivalent O(13) atoms to form corner-sharing SiO4 tetrahedra. In the sixth Si site, Si(6) is bonded to one O(4), one O(8), and two equivalent O(14) atoms to form corner-sharing SiO4 tetrahedra. In the seventh Si site, Si(7) is bonded to one O(3), one O(7), and two equivalent O(11) atoms to form corner-sharing SiO4 tetrahedra. In the eighth Si site, Si(8) is bonded to one O(4), one O(8), and two equivalent O(12) atoms to form corner-sharing SiO4 tetrahedra. C(1) is bonded in a single-bond geometry to one O(3) atom. There are fourteen 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(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Si(5), one Si(7), and one C(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(8) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(7) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(8) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Si(4) and one Si(7) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(8) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(5) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(6) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Si12CO24
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.285
_cell_length_b   11.285
_cell_length_c   5.128
_cell_angle_alpha   89.821
_cell_angle_beta   89.821
_cell_angle_gamma   77.915
_symmetry_Int_Tables_number   1
_cell_volume   638.602
_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
  Si  Si0  1  0.655  0.247  0.948  1.0
  Si  Si1  1  0.247  0.655  0.948  1.0
  Si  Si2  1  0.345  0.752  0.447  1.0
  Si  Si3  1  0.752  0.345  0.447  1.0
  Si  Si4  1  0.585  0.993  0.027  1.0
  Si  Si5  1  0.993  0.585  0.027  1.0
  Si  Si6  1  0.419  0.003  0.529  1.0
  Si  Si7  1  0.003  0.419  0.529  1.0
  Si  Si8  1  0.377  0.377  0.913  1.0
  Si  Si9  1  0.623  0.623  0.424  1.0
  Si  Si10  1  0.269  0.269  0.433  1.0
  Si  Si11  1  0.727  0.727  0.923  1.0
  C  C12  1  0.208  0.208  0.000  1.0
  O  O13  1  0.745  0.294  0.152  1.0
  O  O14  1  0.294  0.745  0.152  1.0
  O  O15  1  0.254  0.705  0.652  1.0
  O  O16  1  0.705  0.254  0.652  1.0
  O  O17  1  0.302  0.302  0.121  1.0
  O  O18  1  0.695  0.695  0.625  1.0
  O  O19  1  0.476  0.008  0.817  1.0
  O  O20  1  0.008  0.476  0.817  1.0
  O  O21  1  0.529  0.985  0.317  1.0
  O  O22  1  0.985  0.529  0.317  1.0
  O  O23  1  0.346  0.346  0.616  1.0
  O  O24  1  0.654  0.654  0.125  1.0
  O  O25  1  0.651  0.108  0.014  1.0
  O  O26  1  0.108  0.651  0.014  1.0
  O  O27  1  0.350  0.890  0.512  1.0
  O  O28  1  0.890  0.350  0.512  1.0
  O  O29  1  0.321  0.127  0.479  1.0
  O  O30  1  0.127  0.321  0.479  1.0
  O  O31  1  0.687  0.872  0.969  1.0
  O  O32  1  0.872  0.687  0.969  1.0
  O  O33  1  0.520  0.335  0.973  1.0
  O  O34  1  0.335  0.520  0.973  1.0
  O  O35  1  0.478  0.663  0.473  1.0
  O  O36  1  0.663  0.478  0.473  1.0
[/CIF]
.