The crystal structure described by Cd4SiSe6 crystallizes in the monoclinic Cc space group. There are four inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one Se(1), one Se(2), one Se(5), and one Se(6) atom to form CdSe4 trigonal pyramids that share corners with two equivalent Cd(4)Se4 tetrahedra, corners with two equivalent Si(1)Se4 tetrahedra, corners with three equivalent Cd(2)Se4 tetrahedra, and corners with three equivalent Cd(3)Se4 tetrahedra. In the second Cd site, Cd(2) is bonded to one Se(1), one Se(2), one Se(4), and one Se(5) atom to form CdSe4 tetrahedra that share corners with two equivalent Cd(3)Se4 tetrahedra, corners with two equivalent Si(1)Se4 tetrahedra, corners with three equivalent Cd(4)Se4 tetrahedra, and corners with three equivalent Cd(1)Se4 trigonal pyramids. In the third Cd site, Cd(3) is bonded to one Se(1), one Se(3), one Se(5), and one Se(6) atom to form CdSe4 tetrahedra that share corners with two equivalent Cd(2)Se4 tetrahedra, corners with two equivalent Si(1)Se4 tetrahedra, corners with three equivalent Cd(4)Se4 tetrahedra, and corners with three equivalent Cd(1)Se4 trigonal pyramids. In the fourth Cd site, Cd(4) is bonded to one Se(1), one Se(3), one Se(4), and one Se(5) atom to form CdSe4 tetrahedra that share corners with two equivalent Si(1)Se4 tetrahedra, corners with three equivalent Cd(2)Se4 tetrahedra, corners with three equivalent Cd(3)Se4 tetrahedra, and corners with two equivalent Cd(1)Se4 trigonal pyramids. Si(1) is bonded to one Se(2), one Se(3), one Se(4), and one Se(6) atom to form SiSe4 tetrahedra that share corners with two equivalent Cd(2)Se4 tetrahedra, corners with two equivalent Cd(3)Se4 tetrahedra, corners with two equivalent Cd(4)Se4 tetrahedra, and corners with two equivalent Cd(1)Se4 trigonal pyramids. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cd(1), one Cd(2), one Cd(3), and one Cd(4) atom to form corner-sharing SeCd4 trigonal pyramids. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one Cd(1), one Cd(2), and one Si(1) atom. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one Cd(3), one Cd(4), and one Si(1) atom. In the fourth Se site, Se(4) is bonded in a trigonal non-coplanar geometry to one Cd(2), one Cd(4), and one Si(1) atom. In the fifth Se site, Se(5) is bonded to one Cd(1), one Cd(2), one Cd(3), and one Cd(4) atom to form corner-sharing SeCd4 tetrahedra. In the sixth Se site, Se(6) is bonded in a distorted trigonal non-coplanar geometry to one Cd(1), one Cd(3), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cd4SiSe6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.576
_cell_length_b   7.576
_cell_length_c   13.139
_cell_angle_alpha   72.524
_cell_angle_beta   72.524
_cell_angle_gamma   59.693
_symmetry_Int_Tables_number   1
_cell_volume   610.792
_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
  Cd  Cd0  1  0.323  0.726  0.691  1.0
  Cd  Cd1  1  0.726  0.323  0.191  1.0
  Cd  Cd2  1  0.088  0.228  0.847  1.0
  Cd  Cd3  1  0.228  0.088  0.347  1.0
  Cd  Cd4  1  0.232  0.445  0.042  1.0
  Cd  Cd5  1  0.445  0.232  0.542  1.0
  Cd  Cd6  1  0.711  0.920  0.854  1.0
  Cd  Cd7  1  0.920  0.711  0.354  1.0
  Si  Si8  1  0.860  0.318  0.604  1.0
  Si  Si9  1  0.318  0.860  0.104  1.0
  Se  Se10  1  0.976  0.442  0.234  1.0
  Se  Se11  1  0.442  0.976  0.734  1.0
  Se  Se12  1  0.033  0.001  0.553  1.0
  Se  Se13  1  0.001  0.033  0.053  1.0
  Se  Se14  1  0.517  0.030  0.053  1.0
  Se  Se15  1  0.030  0.517  0.553  1.0
  Se  Se16  1  0.746  0.287  0.788  1.0
  Se  Se17  1  0.287  0.746  0.288  1.0
  Se  Se18  1  0.085  0.584  0.855  1.0
  Se  Se19  1  0.584  0.085  0.355  1.0
  Se  Se20  1  0.569  0.519  0.524  1.0
  Se  Se21  1  0.519  0.569  0.024  1.0
[/CIF]
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The crystal structure described by Cd4SiSe6 crystallizes in the monoclinic Cc space group. There are four inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one Se(1), one Se(2), one Se(5), and one Se(6) atom to form CdSe4 trigonal pyramids that share corners with two equivalent Cd(4)Se4 tetrahedra, corners with two equivalent Si(1)Se4 tetrahedra, corners with three equivalent Cd(2)Se4 tetrahedra, and corners with three equivalent Cd(3)Se4 tetrahedra. In the second Cd site, Cd(2) is bonded to one Se(1), one Se(2), one Se(4), and one Se(5) atom to form CdSe4 tetrahedra that share corners with two equivalent Cd(3)Se4 tetrahedra, corners with two equivalent Si(1)Se4 tetrahedra, corners with three equivalent Cd(4)Se4 tetrahedra, and corners with three equivalent Cd(1)Se4 trigonal pyramids. In the third Cd site, Cd(3) is bonded to one Se(1), one Se(3), one Se(5), and one Se(6) atom to form CdSe4 tetrahedra that share corners with two equivalent Cd(2)Se4 tetrahedra, corners with two equivalent Si(1)Se4 tetrahedra, corners with three equivalent Cd(4)Se4 tetrahedra, and corners with three equivalent Cd(1)Se4 trigonal pyramids. In the fourth Cd site, Cd(4) is bonded to one Se(1), one Se(3), one Se(4), and one Se(5) atom to form CdSe4 tetrahedra that share corners with two equivalent Si(1)Se4 tetrahedra, corners with three equivalent Cd(2)Se4 tetrahedra, corners with three equivalent Cd(3)Se4 tetrahedra, and corners with two equivalent Cd(1)Se4 trigonal pyramids. Si(1) is bonded to one Se(2), one Se(3), one Se(4), and one Se(6) atom to form SiSe4 tetrahedra that share corners with two equivalent Cd(2)Se4 tetrahedra, corners with two equivalent Cd(3)Se4 tetrahedra, corners with two equivalent Cd(4)Se4 tetrahedra, and corners with two equivalent Cd(1)Se4 trigonal pyramids. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cd(1), one Cd(2), one Cd(3), and one Cd(4) atom to form corner-sharing SeCd4 trigonal pyramids. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one Cd(1), one Cd(2), and one Si(1) atom. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one Cd(3), one Cd(4), and one Si(1) atom. In the fourth Se site, Se(4) is bonded in a trigonal non-coplanar geometry to one Cd(2), one Cd(4), and one Si(1) atom. In the fifth Se site, Se(5) is bonded to one Cd(1), one Cd(2), one Cd(3), and one Cd(4) atom to form corner-sharing SeCd4 tetrahedra. In the sixth Se site, Se(6) is bonded in a distorted trigonal non-coplanar geometry to one Cd(1), one Cd(3), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cd4SiSe6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.576
_cell_length_b   7.576
_cell_length_c   13.139
_cell_angle_alpha   72.524
_cell_angle_beta   72.524
_cell_angle_gamma   59.693
_symmetry_Int_Tables_number   1
_cell_volume   610.792
_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
  Cd  Cd0  1  0.323  0.726  0.691  1.0
  Cd  Cd1  1  0.726  0.323  0.191  1.0
  Cd  Cd2  1  0.088  0.228  0.847  1.0
  Cd  Cd3  1  0.228  0.088  0.347  1.0
  Cd  Cd4  1  0.232  0.445  0.042  1.0
  Cd  Cd5  1  0.445  0.232  0.542  1.0
  Cd  Cd6  1  0.711  0.920  0.854  1.0
  Cd  Cd7  1  0.920  0.711  0.354  1.0
  Si  Si8  1  0.860  0.318  0.604  1.0
  Si  Si9  1  0.318  0.860  0.104  1.0
  Se  Se10  1  0.976  0.442  0.234  1.0
  Se  Se11  1  0.442  0.976  0.734  1.0
  Se  Se12  1  0.033  0.001  0.553  1.0
  Se  Se13  1  0.001  0.033  0.053  1.0
  Se  Se14  1  0.517  0.030  0.053  1.0
  Se  Se15  1  0.030  0.517  0.553  1.0
  Se  Se16  1  0.746  0.287  0.788  1.0
  Se  Se17  1  0.287  0.746  0.288  1.0
  Se  Se18  1  0.085  0.584  0.855  1.0
  Se  Se19  1  0.584  0.085  0.355  1.0
  Se  Se20  1  0.569  0.519  0.524  1.0
  Se  Se21  1  0.519  0.569  0.024  1.0
[/CIF]
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