data_CaEr2W
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   5.18
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaEr2W
_chemical_formula_sum   'Ca1 Er2 W1'
_cell_volume   98.5
_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  Ca0  1  0.0  0.0  0.0  1.0
  Er  Er1  1  0.5  0.5  0.5  1.0
  Er  Er2  1  0.83  0.83  0.83  1.0
  W  W3  1  0.67  0.67  0.67  1.0

data_CaEr2W
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   12.7
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CaEr2W
_chemical_formula_sum   'Ca3 Er6 W3'
_cell_volume   295.51
_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
  Ca  Ca0  3  0.0  0.0  0.0  1.0
  Er  Er1  3  0.0  0.0  0.17  1.0
  Er  Er2  3  0.0  0.0  0.5  1.0
  W  W3  3  0.0  0.0  0.33  1.0

Ca Er Er W
CaEr2W crystallizes in the trigonal R3m space group. Ca(1) is bonded to one Er(2) and three equivalent W(1) atoms to form CaErW3 trigonal pyramids that share  a cornercorner with one W(1)Ca3Er2 trigonal bipyramid and corners with six equivalent Ca(1)ErW3 trigonal pyramids. The Ca(1)-Er(2) bond length is 2.12 Å. All Ca(1)-W(1) bond lengths are 2.99 Å. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a single-bond geometry to one W(1) atom. The Er(1)-W(1) bond length is 2.12 Å. In the second Er site, Er(2) is bonded in a distorted linear geometry to one Ca(1) and one W(1) atom. The Er(2)-W(1) bond length is 2.12 Å. W(1) is bonded to three equivalent Ca(1), one Er(1), and one Er(2) atom to form distorted WCa3Er2 trigonal bipyramids that share corners with six equivalent W(1)Ca3Er2 trigonal bipyramids and  a cornercorner with one Ca(1)ErW3 trigonal pyramid.