data_Er(FeGe)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.86
_cell_length_b   5.86
_cell_length_c   5.86
_cell_angle_alpha   140.82
_cell_angle_beta   140.82
_cell_angle_gamma   56.61
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Er(FeGe)2
_chemical_formula_sum   'Er1 Fe2 Ge2'
_cell_volume   79.68
_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
  Er  Er0  1  0.0  0.0  0.0  1.0
  Fe  Fe1  1  0.96  0.0  0.58  1.0
  Fe  Fe2  1  0.0  0.96  0.58  1.0
  Ge  Ge3  1  0.0  0.0  0.87  1.0
  Ge  Ge4  1  0.0  0.0  0.45  1.0

data_Er(FeGe)2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.56
_cell_length_b   5.56
_cell_length_c   5.86
_cell_angle_alpha   90.0
_cell_angle_beta   118.3
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Er(FeGe)2
_chemical_formula_sum   'Er2 Fe4 Ge4'
_cell_volume   159.36
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Er  Er0  2  0.0  0.0  0.0  1.0
  Fe  Fe1  4  0.48  0.48  0.38  1.0
  Ge  Ge2  2  0.0  0.0  0.13  1.0
  Ge  Ge3  2  0.0  0.0  0.55  1.0

Er Fe Fe Ge Ge
ErFe2Ge2 crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two ErFe2Ge2 clusters. Er(1) is bonded in a distorted single-bond geometry to one Ge(1) and one Ge(2) atom. The Er(1)-Ge(1) bond length is 0.77 Å. The Er(1)-Ge(2) bond length is 2.64 Å. Fe(1) is bonded in a distorted single-bond geometry to one Fe(1) and one Ge(2) atom. The Fe(1)-Fe(1) bond length is 0.20 Å. The Fe(1)-Ge(2) bond length is 0.93 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a single-bond geometry to one Er(1) atom. In the second Ge site, Ge(2) is bonded in a 3-coordinate geometry to one Er(1) and two equivalent Fe(1) atoms.