The compound described by Er2Ge2S7 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to one S(1), one S(2), one S(3), one S(5), one S(7), and two equivalent S(4) atoms to form distorted ErS7 pentagonal bipyramids that share  a cornercorner with one Ge(1)S6 octahedra, corners with two equivalent Er(1)S7 pentagonal bipyramids, corners with two equivalent Ge(2)S4 tetrahedra,  an edgeedge with one Ge(1)S6 octahedra,  an edgeedge with one Ge(2)S4 tetrahedra, and  a faceface with one Ge(1)S6 octahedra. The corner-sharing octahedral tilt angles are 23°. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to one S(1), one S(2), one S(3), one S(6), one S(7), and two equivalent S(5) atoms. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form distorted GeS6 octahedra that share  a cornercorner with one Er(1)S7 pentagonal bipyramid,  an edgeedge with one Er(1)S7 pentagonal bipyramid, faces with two equivalent Ge(1)S6 octahedra, and  a faceface with one Er(1)S7 pentagonal bipyramid. In the second Ge site, Ge(2) is bonded to one S(4), one S(5), one S(6), and one S(7) atom to form GeS4 tetrahedra that share corners with two equivalent Er(1)S7 pentagonal bipyramids and  an edgeedge with one Er(1)S7 pentagonal bipyramid. There are seven inequivalent S sites. In the first S site, S(1) is bonded in a distorted rectangular see-saw-like geometry to one Er(1), one Er(2), and two equivalent Ge(1) atoms. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Er(1), one Er(2), and two equivalent Ge(1) atoms. In the third S site, S(3) is bonded to one Er(1), one Er(2), and two equivalent Ge(1) atoms to form distorted corner-sharing SEr2Ge2 trigonal pyramids. In the fourth S site, S(4) is bonded in a distorted trigonal planar geometry to two equivalent Er(1) and one Ge(2) atom. In the fifth S site, S(5) is bonded in a rectangular see-saw-like geometry to one Er(1), two equivalent Er(2), and one Ge(2) atom. In the sixth S site, S(6) is bonded in an L-shaped geometry to one Er(2) and one Ge(2) atom. In the seventh S site, S(7) is bonded in a trigonal non-coplanar geometry to one Er(1), one Er(2), and one Ge(2) atom. is represented by the CIF card [CIF]
data_Er2Ge2S7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.213
_cell_length_b   9.537
_cell_length_c   9.595
_cell_angle_alpha   61.836
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   501.206
_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
  Er  Er0  1  0.173  0.148  0.607  1.0
  Er  Er1  1  0.172  0.602  0.224  1.0
  Er  Er2  1  0.673  0.852  0.393  1.0
  Er  Er3  1  0.672  0.398  0.776  1.0
  Ge  Ge4  1  0.482  0.992  0.009  1.0
  Ge  Ge5  1  0.982  0.008  0.991  1.0
  Ge  Ge6  1  0.102  0.668  0.669  1.0
  Ge  Ge7  1  0.602  0.332  0.331  1.0
  S  S8  1  0.276  0.221  0.863  1.0
  S  S9  1  0.243  0.865  0.907  1.0
  S  S10  1  0.284  0.880  0.239  1.0
  S  S11  1  0.776  0.779  0.137  1.0
  S  S12  1  0.743  0.135  0.093  1.0
  S  S13  1  0.784  0.120  0.761  1.0
  S  S14  1  0.476  0.084  0.447  1.0
  S  S15  1  0.437  0.425  0.483  1.0
  S  S16  1  0.462  0.489  0.098  1.0
  S  S17  1  0.976  0.916  0.553  1.0
  S  S18  1  0.937  0.575  0.517  1.0
  S  S19  1  0.962  0.511  0.902  1.0
  S  S20  1  0.460  0.675  0.671  1.0
  S  S21  1  0.960  0.325  0.329  1.0
[/CIF]
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The compound described by Er2Ge2S7 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to one S(1), one S(2), one S(3), one S(5), one S(7), and two equivalent S(4) atoms to form distorted ErS7 pentagonal bipyramids that share  a cornercorner with one Ge(1)S6 octahedra, corners with two equivalent Er(1)S7 pentagonal bipyramids, corners with two equivalent Ge(2)S4 tetrahedra,  an edgeedge with one Ge(1)S6 octahedra,  an edgeedge with one Ge(2)S4 tetrahedra, and  a faceface with one Ge(1)S6 octahedra. The corner-sharing octahedral tilt angles are 23°. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to one S(1), one S(2), one S(3), one S(6), one S(7), and two equivalent S(5) atoms. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form distorted GeS6 octahedra that share  a cornercorner with one Er(1)S7 pentagonal bipyramid,  an edgeedge with one Er(1)S7 pentagonal bipyramid, faces with two equivalent Ge(1)S6 octahedra, and  a faceface with one Er(1)S7 pentagonal bipyramid. In the second Ge site, Ge(2) is bonded to one S(4), one S(5), one S(6), and one S(7) atom to form GeS4 tetrahedra that share corners with two equivalent Er(1)S7 pentagonal bipyramids and  an edgeedge with one Er(1)S7 pentagonal bipyramid. There are seven inequivalent S sites. In the first S site, S(1) is bonded in a distorted rectangular see-saw-like geometry to one Er(1), one Er(2), and two equivalent Ge(1) atoms. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Er(1), one Er(2), and two equivalent Ge(1) atoms. In the third S site, S(3) is bonded to one Er(1), one Er(2), and two equivalent Ge(1) atoms to form distorted corner-sharing SEr2Ge2 trigonal pyramids. In the fourth S site, S(4) is bonded in a distorted trigonal planar geometry to two equivalent Er(1) and one Ge(2) atom. In the fifth S site, S(5) is bonded in a rectangular see-saw-like geometry to one Er(1), two equivalent Er(2), and one Ge(2) atom. In the sixth S site, S(6) is bonded in an L-shaped geometry to one Er(2) and one Ge(2) atom. In the seventh S site, S(7) is bonded in a trigonal non-coplanar geometry to one Er(1), one Er(2), and one Ge(2) atom. is represented by the CIF card [CIF]
data_Er2Ge2S7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.213
_cell_length_b   9.537
_cell_length_c   9.595
_cell_angle_alpha   61.836
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   501.206
_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
  Er  Er0  1  0.173  0.148  0.607  1.0
  Er  Er1  1  0.172  0.602  0.224  1.0
  Er  Er2  1  0.673  0.852  0.393  1.0
  Er  Er3  1  0.672  0.398  0.776  1.0
  Ge  Ge4  1  0.482  0.992  0.009  1.0
  Ge  Ge5  1  0.982  0.008  0.991  1.0
  Ge  Ge6  1  0.102  0.668  0.669  1.0
  Ge  Ge7  1  0.602  0.332  0.331  1.0
  S  S8  1  0.276  0.221  0.863  1.0
  S  S9  1  0.243  0.865  0.907  1.0
  S  S10  1  0.284  0.880  0.239  1.0
  S  S11  1  0.776  0.779  0.137  1.0
  S  S12  1  0.743  0.135  0.093  1.0
  S  S13  1  0.784  0.120  0.761  1.0
  S  S14  1  0.476  0.084  0.447  1.0
  S  S15  1  0.437  0.425  0.483  1.0
  S  S16  1  0.462  0.489  0.098  1.0
  S  S17  1  0.976  0.916  0.553  1.0
  S  S18  1  0.937  0.575  0.517  1.0
  S  S19  1  0.962  0.511  0.902  1.0
  S  S20  1  0.460  0.675  0.671  1.0
  S  S21  1  0.960  0.325  0.329  1.0
[/CIF]
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