The compound described by Sr3CaAl8 is Cubic Laves-derived structured and crystallizes in the trigonal R3m space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 12-coordinate geometry to one Sr(2), three equivalent Sr(3), three equivalent Al(2), three equivalent Al(3), and six equivalent Al(4) atoms. In the second Sr site, Sr(2) is bonded in a 16-coordinate geometry to one Sr(1), three equivalent Ca(1), three equivalent Al(1), three equivalent Al(3), and six equivalent Al(4) atoms. In the third Sr site, Sr(3) is bonded in a 16-coordinate geometry to three equivalent Sr(1), one Ca(1), three equivalent Al(2), three equivalent Al(4), and six equivalent Al(3) atoms. Ca(1) is bonded in a 16-coordinate geometry to one Sr(3), three equivalent Sr(2), three equivalent Al(1), three equivalent Al(4), and six equivalent Al(3) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to three equivalent Sr(2), three equivalent Ca(1), three equivalent Al(3), and three equivalent Al(4) atoms to form AlSr3Ca3Al6 cuboctahedra that share corners with six equivalent Al(3)Sr4Ca2Al6 cuboctahedra, corners with six equivalent Al(4)Sr5CaAl6 cuboctahedra, corners with six equivalent Al(2)Sr6Al6 cuboctahedra, edges with six equivalent Al(1)Sr3Ca3Al6 cuboctahedra, faces with nine equivalent Al(3)Sr4Ca2Al6 cuboctahedra, and faces with nine equivalent Al(4)Sr5CaAl6 cuboctahedra. In the second Al site, Al(2) is bonded to three equivalent Sr(1), three equivalent Sr(3), three equivalent Al(3), and three equivalent Al(4) atoms to form AlSr6Al6 cuboctahedra that share corners with six equivalent Al(1)Sr3Ca3Al6 cuboctahedra, corners with six equivalent Al(3)Sr4Ca2Al6 cuboctahedra, corners with six equivalent Al(4)Sr5CaAl6 cuboctahedra, edges with six equivalent Al(2)Sr6Al6 cuboctahedra, faces with nine equivalent Al(3)Sr4Ca2Al6 cuboctahedra, and faces with nine equivalent Al(4)Sr5CaAl6 cuboctahedra. In the third Al site, Al(3) is bonded to one Sr(1), one Sr(2), two equivalent Sr(3), two equivalent Ca(1), one Al(1), one Al(2), and four equivalent Al(3) atoms to form AlSr4Ca2Al6 cuboctahedra that share corners with two equivalent Al(1)Sr3Ca3Al6 cuboctahedra, corners with two equivalent Al(2)Sr6Al6 cuboctahedra, corners with four equivalent Al(3)Sr4Ca2Al6 cuboctahedra, corners with ten equivalent Al(4)Sr5CaAl6 cuboctahedra, edges with two equivalent Al(3)Sr4Ca2Al6 cuboctahedra, edges with four equivalent Al(4)Sr5CaAl6 cuboctahedra, faces with three equivalent Al(1)Sr3Ca3Al6 cuboctahedra, faces with three equivalent Al(2)Sr6Al6 cuboctahedra, faces with four equivalent Al(4)Sr5CaAl6 cuboctahedra, and faces with eight equivalent Al(3)Sr4Ca2Al6 cuboctahedra. In the fourth Al site, Al(4) is bonded to one Sr(3), two equivalent Sr(1), two equivalent Sr(2), one Ca(1), one Al(1), one Al(2), and four equivalent Al(4) atoms to form AlSr5CaAl6 cuboctahedra that share corners with two equivalent Al(1)Sr3Ca3Al6 cuboctahedra, corners with two equivalent Al(2)Sr6Al6 cuboctahedra, corners with four equivalent Al(4)Sr5CaAl6 cuboctahedra, corners with ten equivalent Al(3)Sr4Ca2Al6 cuboctahedra, edges with two equivalent Al(4)Sr5CaAl6 cuboctahedra, edges with four equivalent Al(3)Sr4Ca2Al6 cuboctahedra, faces with three equivalent Al(1)Sr3Ca3Al6 cuboctahedra, faces with three equivalent Al(2)Sr6Al6 cuboctahedra, faces with four equivalent Al(3)Sr4Ca2Al6 cuboctahedra, and faces with eight equivalent Al(4)Sr5CaAl6 cuboctahedra. is represented by the CIF card [CIF]
data_Sr3CaAl8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.061
_cell_length_b   10.061
_cell_length_c   10.061
_cell_angle_alpha   33.404
_cell_angle_beta   33.404
_cell_angle_gamma   33.404
_symmetry_Int_Tables_number   1
_cell_volume   274.867
_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
  Sr  Sr0  1  0.562  0.562  0.562  1.0
  Sr  Sr1  1  0.437  0.437  0.437  1.0
  Sr  Sr2  1  0.938  0.938  0.938  1.0
  Ca  Ca3  1  0.063  0.063  0.063  1.0
  Al  Al4  1  0.750  0.750  0.750  1.0
  Al  Al5  1  0.250  0.250  0.250  1.0
  Al  Al6  1  0.002  0.501  0.501  1.0
  Al  Al7  1  0.498  0.999  0.999  1.0
  Al  Al8  1  0.501  0.002  0.501  1.0
  Al  Al9  1  0.999  0.498  0.999  1.0
  Al  Al10  1  0.501  0.501  0.002  1.0
  Al  Al11  1  0.999  0.999  0.498  1.0
[/CIF]
.
The compound described by Sr3CaAl8 is Cubic Laves-derived structured and crystallizes in the trigonal R3m space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 12-coordinate geometry to one Sr(2), three equivalent Sr(3), three equivalent Al(2), three equivalent Al(3), and six equivalent Al(4) atoms. In the second Sr site, Sr(2) is bonded in a 16-coordinate geometry to one Sr(1), three equivalent Ca(1), three equivalent Al(1), three equivalent Al(3), and six equivalent Al(4) atoms. In the third Sr site, Sr(3) is bonded in a 16-coordinate geometry to three equivalent Sr(1), one Ca(1), three equivalent Al(2), three equivalent Al(4), and six equivalent Al(3) atoms. Ca(1) is bonded in a 16-coordinate geometry to one Sr(3), three equivalent Sr(2), three equivalent Al(1), three equivalent Al(4), and six equivalent Al(3) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to three equivalent Sr(2), three equivalent Ca(1), three equivalent Al(3), and three equivalent Al(4) atoms to form AlSr3Ca3Al6 cuboctahedra that share corners with six equivalent Al(3)Sr4Ca2Al6 cuboctahedra, corners with six equivalent Al(4)Sr5CaAl6 cuboctahedra, corners with six equivalent Al(2)Sr6Al6 cuboctahedra, edges with six equivalent Al(1)Sr3Ca3Al6 cuboctahedra, faces with nine equivalent Al(3)Sr4Ca2Al6 cuboctahedra, and faces with nine equivalent Al(4)Sr5CaAl6 cuboctahedra. In the second Al site, Al(2) is bonded to three equivalent Sr(1), three equivalent Sr(3), three equivalent Al(3), and three equivalent Al(4) atoms to form AlSr6Al6 cuboctahedra that share corners with six equivalent Al(1)Sr3Ca3Al6 cuboctahedra, corners with six equivalent Al(3)Sr4Ca2Al6 cuboctahedra, corners with six equivalent Al(4)Sr5CaAl6 cuboctahedra, edges with six equivalent Al(2)Sr6Al6 cuboctahedra, faces with nine equivalent Al(3)Sr4Ca2Al6 cuboctahedra, and faces with nine equivalent Al(4)Sr5CaAl6 cuboctahedra. In the third Al site, Al(3) is bonded to one Sr(1), one Sr(2), two equivalent Sr(3), two equivalent Ca(1), one Al(1), one Al(2), and four equivalent Al(3) atoms to form AlSr4Ca2Al6 cuboctahedra that share corners with two equivalent Al(1)Sr3Ca3Al6 cuboctahedra, corners with two equivalent Al(2)Sr6Al6 cuboctahedra, corners with four equivalent Al(3)Sr4Ca2Al6 cuboctahedra, corners with ten equivalent Al(4)Sr5CaAl6 cuboctahedra, edges with two equivalent Al(3)Sr4Ca2Al6 cuboctahedra, edges with four equivalent Al(4)Sr5CaAl6 cuboctahedra, faces with three equivalent Al(1)Sr3Ca3Al6 cuboctahedra, faces with three equivalent Al(2)Sr6Al6 cuboctahedra, faces with four equivalent Al(4)Sr5CaAl6 cuboctahedra, and faces with eight equivalent Al(3)Sr4Ca2Al6 cuboctahedra. In the fourth Al site, Al(4) is bonded to one Sr(3), two equivalent Sr(1), two equivalent Sr(2), one Ca(1), one Al(1), one Al(2), and four equivalent Al(4) atoms to form AlSr5CaAl6 cuboctahedra that share corners with two equivalent Al(1)Sr3Ca3Al6 cuboctahedra, corners with two equivalent Al(2)Sr6Al6 cuboctahedra, corners with four equivalent Al(4)Sr5CaAl6 cuboctahedra, corners with ten equivalent Al(3)Sr4Ca2Al6 cuboctahedra, edges with two equivalent Al(4)Sr5CaAl6 cuboctahedra, edges with four equivalent Al(3)Sr4Ca2Al6 cuboctahedra, faces with three equivalent Al(1)Sr3Ca3Al6 cuboctahedra, faces with three equivalent Al(2)Sr6Al6 cuboctahedra, faces with four equivalent Al(3)Sr4Ca2Al6 cuboctahedra, and faces with eight equivalent Al(4)Sr5CaAl6 cuboctahedra. is represented by the CIF card [CIF]
data_Sr3CaAl8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.061
_cell_length_b   10.061
_cell_length_c   10.061
_cell_angle_alpha   33.404
_cell_angle_beta   33.404
_cell_angle_gamma   33.404
_symmetry_Int_Tables_number   1
_cell_volume   274.867
_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
  Sr  Sr0  1  0.562  0.562  0.562  1.0
  Sr  Sr1  1  0.437  0.437  0.437  1.0
  Sr  Sr2  1  0.938  0.938  0.938  1.0
  Ca  Ca3  1  0.063  0.063  0.063  1.0
  Al  Al4  1  0.750  0.750  0.750  1.0
  Al  Al5  1  0.250  0.250  0.250  1.0
  Al  Al6  1  0.002  0.501  0.501  1.0
  Al  Al7  1  0.498  0.999  0.999  1.0
  Al  Al8  1  0.501  0.002  0.501  1.0
  Al  Al9  1  0.999  0.498  0.999  1.0
  Al  Al10  1  0.501  0.501  0.002  1.0
  Al  Al11  1  0.999  0.999  0.498  1.0
[/CIF]
.