The material described by Er2HfS5 crystallizes in the orthorhombic Pnma space group. Er(1) is bonded in a 8-coordinate geometry to two equivalent S(1), two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms. Hf(1) is bonded to one S(2), one S(3), one S(4), and four equivalent S(1) atoms to form distorted edge-sharing HfS7 pentagonal bipyramids. There are four inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Er(1) and two equivalent Hf(1) atoms to form distorted SEr2Hf2 tetrahedra that share corners with four equivalent S(3)Er4Hf square pyramids, corners with six equivalent S(1)Er2Hf2 tetrahedra, corners with two equivalent S(2)Er4Hf trigonal bipyramids, corners with two equivalent S(4)Er4Hf trigonal bipyramids,  an edgeedge with one S(3)Er4Hf square pyramid,  an edgeedge with one S(1)Er2Hf2 tetrahedra, edges with two equivalent S(2)Er4Hf trigonal bipyramids, and edges with two equivalent S(4)Er4Hf trigonal bipyramids. In the second S site, S(2) is bonded to four equivalent Er(1) and one Hf(1) atom to form distorted SEr4Hf trigonal bipyramids that share corners with five equivalent S(3)Er4Hf square pyramids, corners with four equivalent S(1)Er2Hf2 tetrahedra,  a cornercorner with one S(4)Er4Hf trigonal bipyramid, corners with four equivalent S(2)Er4Hf trigonal bipyramids, edges with two equivalent S(3)Er4Hf square pyramids, edges with four equivalent S(1)Er2Hf2 tetrahedra, and edges with four equivalent S(4)Er4Hf trigonal bipyramids. In the third S site, S(3) is bonded to four equivalent Er(1) and one Hf(1) atom to form SEr4Hf square pyramids that share corners with eight equivalent S(1)Er2Hf2 tetrahedra, corners with four equivalent S(4)Er4Hf trigonal bipyramids, corners with five equivalent S(2)Er4Hf trigonal bipyramids, edges with two equivalent S(3)Er4Hf square pyramids, edges with two equivalent S(1)Er2Hf2 tetrahedra,  an edgeedge with one S(4)Er4Hf trigonal bipyramid, edges with two equivalent S(2)Er4Hf trigonal bipyramids, and  a faceface with one S(4)Er4Hf trigonal bipyramid. In the fourth S site, S(4) is bonded to four equivalent Er(1) and one Hf(1) atom to form distorted SEr4Hf trigonal bipyramids that share corners with four equivalent S(3)Er4Hf square pyramids, corners with four equivalent S(1)Er2Hf2 tetrahedra,  a cornercorner with one S(2)Er4Hf trigonal bipyramid, corners with four equivalent S(4)Er4Hf trigonal bipyramids,  an edgeedge with one S(3)Er4Hf square pyramid, edges with four equivalent S(1)Er2Hf2 tetrahedra, edges with four equivalent S(2)Er4Hf trigonal bipyramids, and  a faceface with one S(3)Er4Hf square pyramid. is represented by the CIF file [CIF]
data_Er2HfS5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.214
_cell_length_b   7.679
_cell_length_c   11.517
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   638.027
_cell_formula_units_Z   4
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  0.524  0.003  0.322  1.0
  Er  Er1  1  0.976  0.497  0.822  1.0
  Er  Er2  1  0.476  0.503  0.678  1.0
  Er  Er3  1  0.024  0.997  0.178  1.0
  Er  Er4  1  0.476  0.997  0.678  1.0
  Er  Er5  1  0.024  0.503  0.178  1.0
  Er  Er6  1  0.524  0.497  0.322  1.0
  Er  Er7  1  0.976  0.003  0.822  1.0
  Hf  Hf8  1  0.075  0.750  0.494  1.0
  Hf  Hf9  1  0.425  0.750  0.994  1.0
  Hf  Hf10  1  0.925  0.250  0.506  1.0
  Hf  Hf11  1  0.575  0.250  0.006  1.0
  S  S12  1  0.839  0.536  0.595  1.0
  S  S13  1  0.661  0.964  0.095  1.0
  S  S14  1  0.161  0.036  0.405  1.0
  S  S15  1  0.339  0.464  0.905  1.0
  S  S16  1  0.161  0.464  0.405  1.0
  S  S17  1  0.339  0.036  0.905  1.0
  S  S18  1  0.839  0.964  0.595  1.0
  S  S19  1  0.661  0.536  0.095  1.0
  S  S20  1  0.832  0.750  0.319  1.0
  S  S21  1  0.668  0.750  0.819  1.0
  S  S22  1  0.168  0.250  0.681  1.0
  S  S23  1  0.332  0.250  0.181  1.0
  S  S24  1  0.448  0.750  0.497  1.0
  S  S25  1  0.052  0.750  0.997  1.0
  S  S26  1  0.552  0.250  0.503  1.0
  S  S27  1  0.948  0.250  0.003  1.0
  S  S28  1  0.189  0.750  0.707  1.0
  S  S29  1  0.311  0.750  0.207  1.0
  S  S30  1  0.811  0.250  0.293  1.0
  S  S31  1  0.689  0.250  0.793  1.0
[/CIF]
.
The material described by Er2HfS5 crystallizes in the orthorhombic Pnma space group. Er(1) is bonded in a 8-coordinate geometry to two equivalent S(1), two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms. Hf(1) is bonded to one S(2), one S(3), one S(4), and four equivalent S(1) atoms to form distorted edge-sharing HfS7 pentagonal bipyramids. There are four inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Er(1) and two equivalent Hf(1) atoms to form distorted SEr2Hf2 tetrahedra that share corners with four equivalent S(3)Er4Hf square pyramids, corners with six equivalent S(1)Er2Hf2 tetrahedra, corners with two equivalent S(2)Er4Hf trigonal bipyramids, corners with two equivalent S(4)Er4Hf trigonal bipyramids,  an edgeedge with one S(3)Er4Hf square pyramid,  an edgeedge with one S(1)Er2Hf2 tetrahedra, edges with two equivalent S(2)Er4Hf trigonal bipyramids, and edges with two equivalent S(4)Er4Hf trigonal bipyramids. In the second S site, S(2) is bonded to four equivalent Er(1) and one Hf(1) atom to form distorted SEr4Hf trigonal bipyramids that share corners with five equivalent S(3)Er4Hf square pyramids, corners with four equivalent S(1)Er2Hf2 tetrahedra,  a cornercorner with one S(4)Er4Hf trigonal bipyramid, corners with four equivalent S(2)Er4Hf trigonal bipyramids, edges with two equivalent S(3)Er4Hf square pyramids, edges with four equivalent S(1)Er2Hf2 tetrahedra, and edges with four equivalent S(4)Er4Hf trigonal bipyramids. In the third S site, S(3) is bonded to four equivalent Er(1) and one Hf(1) atom to form SEr4Hf square pyramids that share corners with eight equivalent S(1)Er2Hf2 tetrahedra, corners with four equivalent S(4)Er4Hf trigonal bipyramids, corners with five equivalent S(2)Er4Hf trigonal bipyramids, edges with two equivalent S(3)Er4Hf square pyramids, edges with two equivalent S(1)Er2Hf2 tetrahedra,  an edgeedge with one S(4)Er4Hf trigonal bipyramid, edges with two equivalent S(2)Er4Hf trigonal bipyramids, and  a faceface with one S(4)Er4Hf trigonal bipyramid. In the fourth S site, S(4) is bonded to four equivalent Er(1) and one Hf(1) atom to form distorted SEr4Hf trigonal bipyramids that share corners with four equivalent S(3)Er4Hf square pyramids, corners with four equivalent S(1)Er2Hf2 tetrahedra,  a cornercorner with one S(2)Er4Hf trigonal bipyramid, corners with four equivalent S(4)Er4Hf trigonal bipyramids,  an edgeedge with one S(3)Er4Hf square pyramid, edges with four equivalent S(1)Er2Hf2 tetrahedra, edges with four equivalent S(2)Er4Hf trigonal bipyramids, and  a faceface with one S(3)Er4Hf square pyramid. is represented by the CIF file [CIF]
data_Er2HfS5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.214
_cell_length_b   7.679
_cell_length_c   11.517
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   638.027
_cell_formula_units_Z   4
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  0.524  0.003  0.322  1.0
  Er  Er1  1  0.976  0.497  0.822  1.0
  Er  Er2  1  0.476  0.503  0.678  1.0
  Er  Er3  1  0.024  0.997  0.178  1.0
  Er  Er4  1  0.476  0.997  0.678  1.0
  Er  Er5  1  0.024  0.503  0.178  1.0
  Er  Er6  1  0.524  0.497  0.322  1.0
  Er  Er7  1  0.976  0.003  0.822  1.0
  Hf  Hf8  1  0.075  0.750  0.494  1.0
  Hf  Hf9  1  0.425  0.750  0.994  1.0
  Hf  Hf10  1  0.925  0.250  0.506  1.0
  Hf  Hf11  1  0.575  0.250  0.006  1.0
  S  S12  1  0.839  0.536  0.595  1.0
  S  S13  1  0.661  0.964  0.095  1.0
  S  S14  1  0.161  0.036  0.405  1.0
  S  S15  1  0.339  0.464  0.905  1.0
  S  S16  1  0.161  0.464  0.405  1.0
  S  S17  1  0.339  0.036  0.905  1.0
  S  S18  1  0.839  0.964  0.595  1.0
  S  S19  1  0.661  0.536  0.095  1.0
  S  S20  1  0.832  0.750  0.319  1.0
  S  S21  1  0.668  0.750  0.819  1.0
  S  S22  1  0.168  0.250  0.681  1.0
  S  S23  1  0.332  0.250  0.181  1.0
  S  S24  1  0.448  0.750  0.497  1.0
  S  S25  1  0.052  0.750  0.997  1.0
  S  S26  1  0.552  0.250  0.503  1.0
  S  S27  1  0.948  0.250  0.003  1.0
  S  S28  1  0.189  0.750  0.707  1.0
  S  S29  1  0.311  0.750  0.207  1.0
  S  S30  1  0.811  0.250  0.293  1.0
  S  S31  1  0.689  0.250  0.793  1.0
[/CIF]
.