The crystal structure described by Ca3Cu2Al7 crystallizes in the trigonal R-3m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 18-coordinate geometry to six equivalent Cu(1) and twelve equivalent Al(2) atoms. In the second Ca site, Ca(2) is bonded in a 12-coordinate geometry to three equivalent Al(1) and nine equivalent Al(2) atoms. Cu(1) is bonded in a 9-coordinate geometry to three equivalent Ca(1) and six equivalent Al(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to six equivalent Ca(2) and six equivalent Al(2) atoms to form AlCa6Al6 cuboctahedra that share corners with twelve equivalent Al(2)Ca5Al5Cu2 cuboctahedra, edges with six equivalent Al(1)Ca6Al6 cuboctahedra, and faces with eighteen equivalent Al(2)Ca5Al5Cu2 cuboctahedra. In the second Al site, Al(2) is bonded to two equivalent Ca(1), three equivalent Ca(2), two equivalent Cu(1), one Al(1), and four equivalent Al(2) atoms to form distorted AlCa5Al5Cu2 cuboctahedra that share corners with two equivalent Al(1)Ca6Al6 cuboctahedra, corners with fifteen equivalent Al(2)Ca5Al5Cu2 cuboctahedra, edges with eight equivalent Al(2)Ca5Al5Cu2 cuboctahedra, faces with three equivalent Al(1)Ca6Al6 cuboctahedra, and faces with eleven equivalent Al(2)Ca5Al5Cu2 cuboctahedra. is represented by the CIF card [CIF]
data_Ca3Al7Cu2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.139
_cell_length_b   9.139
_cell_length_c   9.139
_cell_angle_alpha   35.370
_cell_angle_beta   35.370
_cell_angle_gamma   35.370
_symmetry_Int_Tables_number   1
_cell_volume   228.518
_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
  Ca  Ca0  1  0.000  0.000  0.000  1.0
  Ca  Ca1  1  0.143  0.143  0.143  1.0
  Ca  Ca2  1  0.857  0.857  0.857  1.0
  Al  Al3  1  0.500  0.500  0.500  1.0
  Al  Al4  1  0.578  0.073  0.578  1.0
  Al  Al5  1  0.578  0.578  0.073  1.0
  Al  Al6  1  0.073  0.578  0.578  1.0
  Al  Al7  1  0.927  0.422  0.422  1.0
  Al  Al8  1  0.422  0.927  0.422  1.0
  Al  Al9  1  0.422  0.422  0.927  1.0
  Cu  Cu10  1  0.335  0.335  0.335  1.0
  Cu  Cu11  1  0.665  0.665  0.665  1.0
[/CIF]
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The crystal structure described by Ca3Cu2Al7 crystallizes in the trigonal R-3m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 18-coordinate geometry to six equivalent Cu(1) and twelve equivalent Al(2) atoms. In the second Ca site, Ca(2) is bonded in a 12-coordinate geometry to three equivalent Al(1) and nine equivalent Al(2) atoms. Cu(1) is bonded in a 9-coordinate geometry to three equivalent Ca(1) and six equivalent Al(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to six equivalent Ca(2) and six equivalent Al(2) atoms to form AlCa6Al6 cuboctahedra that share corners with twelve equivalent Al(2)Ca5Al5Cu2 cuboctahedra, edges with six equivalent Al(1)Ca6Al6 cuboctahedra, and faces with eighteen equivalent Al(2)Ca5Al5Cu2 cuboctahedra. In the second Al site, Al(2) is bonded to two equivalent Ca(1), three equivalent Ca(2), two equivalent Cu(1), one Al(1), and four equivalent Al(2) atoms to form distorted AlCa5Al5Cu2 cuboctahedra that share corners with two equivalent Al(1)Ca6Al6 cuboctahedra, corners with fifteen equivalent Al(2)Ca5Al5Cu2 cuboctahedra, edges with eight equivalent Al(2)Ca5Al5Cu2 cuboctahedra, faces with three equivalent Al(1)Ca6Al6 cuboctahedra, and faces with eleven equivalent Al(2)Ca5Al5Cu2 cuboctahedra. is represented by the CIF card [CIF]
data_Ca3Al7Cu2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.139
_cell_length_b   9.139
_cell_length_c   9.139
_cell_angle_alpha   35.370
_cell_angle_beta   35.370
_cell_angle_gamma   35.370
_symmetry_Int_Tables_number   1
_cell_volume   228.518
_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
  Ca  Ca0  1  0.000  0.000  0.000  1.0
  Ca  Ca1  1  0.143  0.143  0.143  1.0
  Ca  Ca2  1  0.857  0.857  0.857  1.0
  Al  Al3  1  0.500  0.500  0.500  1.0
  Al  Al4  1  0.578  0.073  0.578  1.0
  Al  Al5  1  0.578  0.578  0.073  1.0
  Al  Al6  1  0.073  0.578  0.578  1.0
  Al  Al7  1  0.927  0.422  0.422  1.0
  Al  Al8  1  0.422  0.927  0.422  1.0
  Al  Al9  1  0.422  0.422  0.927  1.0
  Cu  Cu10  1  0.335  0.335  0.335  1.0
  Cu  Cu11  1  0.665  0.665  0.665  1.0
[/CIF]
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