data_AcCe2Ni
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.45
_cell_length_b   5.45
_cell_length_c   5.45
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   AcCe2Ni
_chemical_formula_sum   'Ac1 Ce2 Ni1'
_cell_volume   114.7
_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
  Ac  Ac0  1  0.86  0.86  0.86  1.0
  Ce  Ce1  1  0.78  0.78  0.78  1.0
  Ce  Ce2  1  0.93  0.93  0.93  1.0
  Ni  Ni3  1  0.0  0.0  0.0  1.0

data_AcCe2Ni
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.45
_cell_length_b   5.45
_cell_length_c   13.36
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   AcCe2Ni
_chemical_formula_sum   'Ac3 Ce6 Ni3'
_cell_volume   344.1
_cell_formula_units_Z   3
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  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+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
  Ac  Ac0  3  0.0  0.0  0.14  1.0
  Ce  Ce1  3  0.0  0.0  0.07  1.0
  Ce  Ce2  3  0.0  0.0  0.22  1.0
  Ni  Ni3  3  0.0  0.0  0.0  1.0

Ac Ce Ce Ni
AcCe2Ni crystallizes in the trigonal R3m space group. Ac(1) is bonded in a linear geometry to one Ce(1) and one Ce(2) atom. The Ac(1)-Ce(1) bond length is 0.96 Å. The Ac(1)-Ce(2) bond length is 0.96 Å. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Ac(1) and three equivalent Ni(1) atoms to form distorted corner-sharing CeAcNi3 tetrahedra. All Ce(1)-Ni(1) bond lengths are 3.52 Å. In the second Ce site, Ce(2) is bonded in a distorted linear geometry to one Ac(1) and one Ni(1) atom. The Ce(2)-Ni(1) bond length is 0.96 Å. Ni(1) is bonded in a single-bond geometry to one Ce(2) and three equivalent Ce(1) atoms.