The crystal structure described by BaAc3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Ba(1) is bonded to twelve Ac(1,1,1) atoms to form BaAc12 cuboctahedra that share corners with six equivalent Ba(1)Ac12 cuboctahedra; corners with twelve Ac(1,1)Ba4Ac8 cuboctahedra; edges with eighteen Ac(1,1,1)Ba4Ac8 cuboctahedra; faces with eight equivalent Ba(1)Ac12 cuboctahedra; and faces with twelve Ac(1,1,1)Ba4Ac8 cuboctahedra. There are three inequivalent Ac sites. In the first Ac site, Ac(1) is bonded to four equivalent Ba(1) and eight Ac(1,1,1) atoms to form AcBa4Ac8 cuboctahedra that share corners with four equivalent Ba(1)Ac12 cuboctahedra; corners with fourteen Ac(1,1)Ba4Ac8 cuboctahedra; edges with six equivalent Ba(1)Ac12 cuboctahedra; edges with twelve Ac(1,1,1)Ba4Ac8 cuboctahedra; faces with four equivalent Ba(1)Ac12 cuboctahedra; and faces with sixteen Ac(1,1,1)Ba4Ac8 cuboctahedra. In the second Ac site, Ac(1) is bonded to four equivalent Ba(1) and eight equivalent Ac(1) atoms to form AcBa4Ac8 cuboctahedra that share corners with four equivalent Ba(1)Ac12 cuboctahedra; corners with fourteen Ac(1,1)Ba4Ac8 cuboctahedra; edges with six equivalent Ba(1)Ac12 cuboctahedra; edges with twelve equivalent Ac(1)Ba4Ac8 cuboctahedra; faces with four equivalent Ba(1)Ac12 cuboctahedra; and faces with sixteen Ac(1,1,1)Ba4Ac8 cuboctahedra. In the third Ac site, Ac(1) is bonded to four equivalent Ba(1) and eight equivalent Ac(1) atoms to form AcBa4Ac8 cuboctahedra that share corners with four equivalent Ba(1)Ac12 cuboctahedra; corners with fourteen Ac(1,1)Ba4Ac8 cuboctahedra; edges with six equivalent Ba(1)Ac12 cuboctahedra; edges with twelve equivalent Ac(1)Ba4Ac8 cuboctahedra; faces with four equivalent Ba(1)Ac12 cuboctahedra; and faces with sixteen Ac(1,1,1)Ba4Ac8 cuboctahedra. is represented by the CIF file [CIF]
data_BaAc3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.240
_cell_length_b   8.240
_cell_length_c   6.589
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   387.482
_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
  Ba  Ba0  1  0.333  0.667  0.750  1.0
  Ba  Ba1  1  0.667  0.333  0.250  1.0
  Ac  Ac2  1  0.162  0.324  0.250  1.0
  Ac  Ac3  1  0.676  0.838  0.250  1.0
  Ac  Ac4  1  0.162  0.838  0.250  1.0
  Ac  Ac5  1  0.838  0.676  0.750  1.0
  Ac  Ac6  1  0.324  0.162  0.750  1.0
  Ac  Ac7  1  0.838  0.162  0.750  1.0
[/CIF]
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The crystal structure described by BaAc3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Ba(1) is bonded to twelve Ac(1,1,1) atoms to form BaAc12 cuboctahedra that share corners with six equivalent Ba(1)Ac12 cuboctahedra; corners with twelve Ac(1,1)Ba4Ac8 cuboctahedra; edges with eighteen Ac(1,1,1)Ba4Ac8 cuboctahedra; faces with eight equivalent Ba(1)Ac12 cuboctahedra; and faces with twelve Ac(1,1,1)Ba4Ac8 cuboctahedra. There are three inequivalent Ac sites. In the first Ac site, Ac(1) is bonded to four equivalent Ba(1) and eight Ac(1,1,1) atoms to form AcBa4Ac8 cuboctahedra that share corners with four equivalent Ba(1)Ac12 cuboctahedra; corners with fourteen Ac(1,1)Ba4Ac8 cuboctahedra; edges with six equivalent Ba(1)Ac12 cuboctahedra; edges with twelve Ac(1,1,1)Ba4Ac8 cuboctahedra; faces with four equivalent Ba(1)Ac12 cuboctahedra; and faces with sixteen Ac(1,1,1)Ba4Ac8 cuboctahedra. In the second Ac site, Ac(1) is bonded to four equivalent Ba(1) and eight equivalent Ac(1) atoms to form AcBa4Ac8 cuboctahedra that share corners with four equivalent Ba(1)Ac12 cuboctahedra; corners with fourteen Ac(1,1)Ba4Ac8 cuboctahedra; edges with six equivalent Ba(1)Ac12 cuboctahedra; edges with twelve equivalent Ac(1)Ba4Ac8 cuboctahedra; faces with four equivalent Ba(1)Ac12 cuboctahedra; and faces with sixteen Ac(1,1,1)Ba4Ac8 cuboctahedra. In the third Ac site, Ac(1) is bonded to four equivalent Ba(1) and eight equivalent Ac(1) atoms to form AcBa4Ac8 cuboctahedra that share corners with four equivalent Ba(1)Ac12 cuboctahedra; corners with fourteen Ac(1,1)Ba4Ac8 cuboctahedra; edges with six equivalent Ba(1)Ac12 cuboctahedra; edges with twelve equivalent Ac(1)Ba4Ac8 cuboctahedra; faces with four equivalent Ba(1)Ac12 cuboctahedra; and faces with sixteen Ac(1,1,1)Ba4Ac8 cuboctahedra. is represented by the CIF file [CIF]
data_BaAc3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.240
_cell_length_b   8.240
_cell_length_c   6.589
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   387.482
_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
  Ba  Ba0  1  0.333  0.667  0.750  1.0
  Ba  Ba1  1  0.667  0.333  0.250  1.0
  Ac  Ac2  1  0.162  0.324  0.250  1.0
  Ac  Ac3  1  0.676  0.838  0.250  1.0
  Ac  Ac4  1  0.162  0.838  0.250  1.0
  Ac  Ac5  1  0.838  0.676  0.750  1.0
  Ac  Ac6  1  0.324  0.162  0.750  1.0
  Ac  Ac7  1  0.838  0.162  0.750  1.0
[/CIF]
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