The structure described by CaAlSi crystallizes in the trigonal P3m1 space group. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to three equivalent Al(1), three equivalent Al(5), three equivalent Si(3), and three equivalent Si(4) atoms to form a mixture of distorted face and edge-sharing CaAl6Si6 cuboctahedra. In the second Ca site, Ca(2) is bonded to three equivalent Al(2), three equivalent Al(3), three equivalent Si(1), and three equivalent Si(2) atoms to form a mixture of distorted face and edge-sharing CaAl6Si6 cuboctahedra. In the third Ca site, Ca(3) is bonded to three equivalent Al(3), three equivalent Al(4), three equivalent Si(2), and three equivalent Si(5) atoms to form a mixture of face and edge-sharing CaAl6Si6 cuboctahedra. In the fourth Ca site, Ca(4) is bonded to three equivalent Al(4), three equivalent Al(5), three equivalent Si(3), and three equivalent Si(5) atoms to form a mixture of face and edge-sharing CaAl6Si6 cuboctahedra. In the fifth Ca site, Ca(5) is bonded to three equivalent Al(1), three equivalent Al(2), three equivalent Si(1), and three equivalent Si(4) atoms to form a mixture of distorted face and edge-sharing CaAl6Si6 cuboctahedra. There are five inequivalent Al sites. In the first Al site, Al(1) is bonded in a 9-coordinate geometry to three equivalent Ca(1), three equivalent Ca(5), and three equivalent Si(4) atoms. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ca(5), and three equivalent Si(1) atoms. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ca(3), and three equivalent Si(2) atoms. In the fourth Al site, Al(4) is bonded in a distorted trigonal planar geometry to three equivalent Ca(3), three equivalent Ca(4), and three equivalent Si(5) atoms. In the fifth Al site, Al(5) is bonded in a 9-coordinate geometry to three equivalent Ca(1), three equivalent Ca(4), and three equivalent Si(3) atoms. There are five inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ca(5), and three equivalent Al(2) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ca(3), and three equivalent Al(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to three equivalent Ca(1), three equivalent Ca(4), and three equivalent Al(5) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to three equivalent Ca(1), three equivalent Ca(5), and three equivalent Al(1) atoms. In the fifth Si site, Si(5) is bonded in a distorted trigonal planar geometry to three equivalent Ca(3), three equivalent Ca(4), and three equivalent Al(4) atoms. is represented by the CIF card [CIF]
data_CaAlSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.191
_cell_length_b   4.191
_cell_length_c   21.946
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   333.761
_cell_formula_units_Z   5
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
  Ca  Ca0  1  0.000  0.000  0.999  1.0
  Ca  Ca1  1  0.000  0.000  0.602  1.0
  Ca  Ca2  1  0.000  0.000  0.399  1.0
  Ca  Ca3  1  0.000  0.000  0.201  1.0
  Ca  Ca4  1  0.000  0.000  0.800  1.0
  Al  Al5  1  0.333  0.667  0.890  1.0
  Al  Al6  1  0.333  0.667  0.711  1.0
  Al  Al7  1  0.667  0.333  0.494  1.0
  Al  Al8  1  0.667  0.333  0.300  1.0
  Al  Al9  1  0.667  0.333  0.107  1.0
  Si  Si10  1  0.667  0.333  0.695  1.0
  Si  Si11  1  0.333  0.667  0.506  1.0
  Si  Si12  1  0.333  0.667  0.094  1.0
  Si  Si13  1  0.667  0.333  0.906  1.0
  Si  Si14  1  0.333  0.667  0.301  1.0
[/CIF]
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The structure described by CaAlSi crystallizes in the trigonal P3m1 space group. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to three equivalent Al(1), three equivalent Al(5), three equivalent Si(3), and three equivalent Si(4) atoms to form a mixture of distorted face and edge-sharing CaAl6Si6 cuboctahedra. In the second Ca site, Ca(2) is bonded to three equivalent Al(2), three equivalent Al(3), three equivalent Si(1), and three equivalent Si(2) atoms to form a mixture of distorted face and edge-sharing CaAl6Si6 cuboctahedra. In the third Ca site, Ca(3) is bonded to three equivalent Al(3), three equivalent Al(4), three equivalent Si(2), and three equivalent Si(5) atoms to form a mixture of face and edge-sharing CaAl6Si6 cuboctahedra. In the fourth Ca site, Ca(4) is bonded to three equivalent Al(4), three equivalent Al(5), three equivalent Si(3), and three equivalent Si(5) atoms to form a mixture of face and edge-sharing CaAl6Si6 cuboctahedra. In the fifth Ca site, Ca(5) is bonded to three equivalent Al(1), three equivalent Al(2), three equivalent Si(1), and three equivalent Si(4) atoms to form a mixture of distorted face and edge-sharing CaAl6Si6 cuboctahedra. There are five inequivalent Al sites. In the first Al site, Al(1) is bonded in a 9-coordinate geometry to three equivalent Ca(1), three equivalent Ca(5), and three equivalent Si(4) atoms. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ca(5), and three equivalent Si(1) atoms. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ca(3), and three equivalent Si(2) atoms. In the fourth Al site, Al(4) is bonded in a distorted trigonal planar geometry to three equivalent Ca(3), three equivalent Ca(4), and three equivalent Si(5) atoms. In the fifth Al site, Al(5) is bonded in a 9-coordinate geometry to three equivalent Ca(1), three equivalent Ca(4), and three equivalent Si(3) atoms. There are five inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ca(5), and three equivalent Al(2) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ca(3), and three equivalent Al(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to three equivalent Ca(1), three equivalent Ca(4), and three equivalent Al(5) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to three equivalent Ca(1), three equivalent Ca(5), and three equivalent Al(1) atoms. In the fifth Si site, Si(5) is bonded in a distorted trigonal planar geometry to three equivalent Ca(3), three equivalent Ca(4), and three equivalent Al(4) atoms. is represented by the CIF card [CIF]
data_CaAlSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.191
_cell_length_b   4.191
_cell_length_c   21.946
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   333.761
_cell_formula_units_Z   5
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
  Ca  Ca0  1  0.000  0.000  0.999  1.0
  Ca  Ca1  1  0.000  0.000  0.602  1.0
  Ca  Ca2  1  0.000  0.000  0.399  1.0
  Ca  Ca3  1  0.000  0.000  0.201  1.0
  Ca  Ca4  1  0.000  0.000  0.800  1.0
  Al  Al5  1  0.333  0.667  0.890  1.0
  Al  Al6  1  0.333  0.667  0.711  1.0
  Al  Al7  1  0.667  0.333  0.494  1.0
  Al  Al8  1  0.667  0.333  0.300  1.0
  Al  Al9  1  0.667  0.333  0.107  1.0
  Si  Si10  1  0.667  0.333  0.695  1.0
  Si  Si11  1  0.333  0.667  0.506  1.0
  Si  Si12  1  0.333  0.667  0.094  1.0
  Si  Si13  1  0.667  0.333  0.906  1.0
  Si  Si14  1  0.333  0.667  0.301  1.0
[/CIF]
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