data_Ca3Sc
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.68
_cell_length_b   6.68
_cell_length_c   6.68
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca3Sc
_chemical_formula_sum   'Ca6 Sc2'
_cell_volume   298.51
_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
  Ca  Ca0  1  0.67  0.0  0.34  1.0
  Ca  Ca1  1  0.01  0.0  0.34  1.0
  Ca  Ca2  1  0.34  0.67  0.0  1.0
  Ca  Ca3  1  0.34  0.01  0.0  1.0
  Ca  Ca4  1  0.0  0.34  0.01  1.0
  Ca  Ca5  1  0.0  0.34  0.67  1.0
  Sc  Sc6  1  0.34  0.34  0.34  1.0
  Sc  Sc7  1  0.0  0.0  0.0  1.0

data_Ca3Sc
_symmetry_space_group_name_H-M   R3
_cell_length_a   9.45
_cell_length_b   9.45
_cell_length_c   11.58
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   Ca3Sc
_chemical_formula_sum   'Ca18 Sc6'
_cell_volume   895.54
_cell_formula_units_Z   6
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  'x+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+1/3, z+1/3'
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  9  0.0  0.34  0.34  1.0
  Ca  Ca1  9  0.22  0.77  0.78  1.0
  Sc  Sc2  3  0.0  0.0  0.0  1.0
  Sc  Sc3  3  0.0  0.0  0.34  1.0

Ca Ca Ca Ca Ca Ca Sc Sc
Ca3Sc crystallizes in the trigonal R3 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 4-coordinate geometry to two equivalent Ca(2), one Sc(1), and one Sc(2) atom. There is one shorter (2.28 Å) and one longer (3.17 Å) Ca(1)-Ca(2) bond length. The Ca(1)-Sc(1) bond length is 3.17 Å. The Ca(1)-Sc(2) bond length is 3.17 Å. In the second Ca site, Ca(2) is bonded in a distorted single-bond geometry to two equivalent Ca(1), one Sc(1), and one Sc(2) atom. The Ca(2)-Sc(1) bond length is 3.17 Å. The Ca(2)-Sc(2) bond length is 2.28 Å. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a distorted hexagonal planar geometry to three equivalent Ca(1) and three equivalent Ca(2) atoms. In the second Sc site, Sc(2) is bonded in a 3-coordinate geometry to three equivalent Ca(1) and three equivalent Ca(2) atoms.