data_Ca2AlSb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.27
_cell_length_b   4.27
_cell_length_c   6.44
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca2AlSb
_chemical_formula_sum   'Ca2 Al1 Sb1'
_cell_volume   117.53
_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  Ca1  1  0.14  0.14  0.19  1.0
  Ca  Ca2  1  0.0  0.0  0.87  1.0
  Al  Al0  1  0.0  0.0  0.93  1.0
  Sb  Sb3  1  0.14  0.14  0.11  1.0

data_Ca2AlSb
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.04
_cell_length_b   6.04
_cell_length_c   6.44
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ca2AlSb
_chemical_formula_sum   'Ca4 Al2 Sb2'
_cell_volume   235.06
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.87  1.0
  Ca  Ca1  2  0.14  0.0  0.19  1.0
  Al  Al2  2  0.0  0.0  0.93  1.0
  Sb  Sb3  2  0.14  0.0  0.11  1.0

Ca Ca Al Sb
Ca Ca Al Sb 0 3 o o o 1 2 o o o 
Ca2AlSb is alpha Niobium phosphide-derived structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Ca2AlSb clusters. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a single-bond geometry to one Sb(1) atom. The Ca(1)-Sb(1) bond length is 0.48 Å. In the second Ca site, Ca(2) is bonded in a single-bond geometry to one Al(1) atom. The Ca(2)-Al(1) bond length is 0.35 Å. Al(1) is bonded in a bent 150 degrees geometry to one Ca(2) and one Sb(1) atom. The Al(1)-Sb(1) bond length is 1.46 Å. Sb(1) is bonded in a bent 150 degrees geometry to one Ca(1) and one Al(1) atom.