data_Ce2EuSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.44
_cell_length_b   5.44
_cell_length_c   5.44
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ce2EuSi
_chemical_formula_sum   'Ce2 Eu1 Si1'
_cell_volume   113.53
_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
  Ce  Ce0  1  0.76  0.76  0.76  1.0
  Ce  Ce1  1  0.92  0.92  0.92  1.0
  Eu  Eu2  1  0.84  0.84  0.84  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0

data_Ce2EuSi
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.44
_cell_length_b   5.44
_cell_length_c   13.31
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Ce2EuSi
_chemical_formula_sum   'Ce6 Eu3 Si3'
_cell_volume   340.6
_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
  Ce  Ce0  3  0.0  0.0  0.08  1.0
  Ce  Ce1  3  0.0  0.0  0.24  1.0
  Eu  Eu2  3  0.0  0.0  0.16  1.0
  Si  Si3  3  0.0  0.0  0.0  1.0

Ce Ce Eu Si
Ce Ce Eu Si 0 2 o o o 1 2 o o o 1 3 + + + 
EuCe2Si crystallizes in the trigonal R3m space group. Eu(1) is bonded in a linear geometry to one Ce(1) and one Ce(2) atom. The Eu(1)-Ce(1) bond length is 1.04 Å. The Eu(1)-Ce(2) bond length is 1.04 Å. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Eu(1) and three equivalent Si(1) atoms to form distorted corner-sharing CeEuSi3 tetrahedra. All Ce(1)-Si(1) bond lengths are 3.40 Å. In the second Ce site, Ce(2) is bonded in a distorted linear geometry to one Eu(1) and one Si(1) atom. The Ce(2)-Si(1) bond length is 1.04 Å. Si(1) is bonded in a single-bond geometry to one Ce(2) and three equivalent Ce(1) atoms.