The compound described by Er7Cu3Te12 is Corundum-derived structured and crystallizes in the monoclinic Cm space group. There are five inequivalent Er sites. In the first Er site, Er(1) is bonded to one Te(6), one Te(8), two equivalent Te(2), and two equivalent Te(5) atoms to form ErTe6 octahedra that share  a cornercorner with one Er(3)Te6 octahedra,  a cornercorner with one Cu(2)Te4 tetrahedra, corners with two equivalent Cu(1)Te4 tetrahedra,  an edgeedge with one Er(3)Te6 octahedra, edges with three equivalent Er(1)Te6 octahedra, and edges with three equivalent Er(5)Te6 octahedra. The corner-sharing octahedral tilt angles are 3°. In the second Er site, Er(2) is bonded to one Te(4), one Te(7), two equivalent Te(1), and two equivalent Te(3) atoms to form ErTe6 octahedra that share  a cornercorner with one Er(3)Te6 octahedra,  a cornercorner with one Cu(2)Te4 tetrahedra, corners with two equivalent Cu(1)Te4 tetrahedra,  an edgeedge with one Er(3)Te6 octahedra, edges with three equivalent Er(2)Te6 octahedra, edges with three equivalent Er(4)Te6 octahedra,  an edgeedge with one Cu(2)Te4 tetrahedra, and edges with two equivalent Cu(1)Te4 tetrahedra. The corner-sharing octahedral tilt angles are 1°. In the third Er site, Er(3) is bonded to one Te(6), one Te(7), two equivalent Te(2), and two equivalent Te(3) atoms to form a mixture of corner and edge-sharing ErTe6 octahedra. The corner-sharing octahedral tilt angles range from 1-3°. In the fourth Er site, Er(4) is bonded to one Te(4), one Te(7), two equivalent Te(1), and two equivalent Te(3) atoms to form ErTe6 octahedra that share  a cornercorner with one Er(3)Te6 octahedra,  a cornercorner with one Cu(2)Te4 tetrahedra, corners with two equivalent Cu(1)Te4 tetrahedra,  an edgeedge with one Er(3)Te6 octahedra, edges with six equivalent Er(2)Te6 octahedra,  an edgeedge with one Cu(2)Te4 tetrahedra, and edges with two equivalent Cu(1)Te4 tetrahedra. The corner-sharing octahedral tilt angles are 1°. In the fifth Er site, Er(5) is bonded to one Te(6), one Te(8), two equivalent Te(2), and two equivalent Te(5) atoms to form ErTe6 octahedra that share  a cornercorner with one Er(3)Te6 octahedra,  a cornercorner with one Cu(2)Te4 tetrahedra, corners with two equivalent Cu(1)Te4 tetrahedra,  an edgeedge with one Er(3)Te6 octahedra, and edges with six equivalent Er(1)Te6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Te(4), one Te(5), and two equivalent Te(1) atoms to form CuTe4 tetrahedra that share  a cornercorner with one Er(4)Te6 octahedra,  a cornercorner with one Er(5)Te6 octahedra, corners with two equivalent Er(1)Te6 octahedra, corners with two equivalent Er(2)Te6 octahedra, corners with three equivalent Cu(1)Te4 tetrahedra, corners with three equivalent Cu(2)Te4 tetrahedra,  an edgeedge with one Er(4)Te6 octahedra, and edges with two equivalent Er(2)Te6 octahedra. The corner-sharing octahedral tilt angles range from 19-56°. In the second Cu site, Cu(2) is bonded to one Te(4), one Te(8), and two equivalent Te(1) atoms to form CuTe4 tetrahedra that share  a cornercorner with one Er(4)Te6 octahedra,  a cornercorner with one Er(5)Te6 octahedra, corners with two equivalent Er(1)Te6 octahedra, corners with two equivalent Er(2)Te6 octahedra, corners with six equivalent Cu(1)Te4 tetrahedra,  an edgeedge with one Er(4)Te6 octahedra, and edges with two equivalent Er(2)Te6 octahedra. The corner-sharing octahedral tilt angles range from 19-55°. There are eight inequivalent Te sites. In the first Te site, Te(1) is bonded to one Er(4), two equivalent Er(2), one Cu(2), and two equivalent Cu(1) atoms to form distorted edge-sharing TeEr3Cu3 octahedra. In the second Te site, Te(2) is bonded in a rectangular see-saw-like geometry to one Er(3), one Er(5), and two equivalent Er(1) atoms. In the third Te site, Te(3) is bonded in a rectangular see-saw-like geometry to one Er(3), one Er(4), and two equivalent Er(2) atoms. In the fourth Te site, Te(4) is bonded to one Er(4), two equivalent Er(2), one Cu(2), and two equivalent Cu(1) atoms to form distorted edge-sharing TeEr3Cu3 octahedra. In the fifth Te site, Te(5) is bonded in a rectangular see-saw-like geometry to one Er(5), two equivalent Er(1), and one Cu(1) atom. In the sixth Te site, Te(6) is bonded in a rectangular see-saw-like geometry to one Er(3), one Er(5), and two equivalent Er(1) atoms. In the seventh Te site, Te(7) is bonded in a rectangular see-saw-like geometry to one Er(3), one Er(4), and two equivalent Er(2) atoms. In the eighth Te site, Te(8) is bonded in a rectangular see-saw-like geometry to one Er(5), two equivalent Er(1), and one Cu(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Er7(CuTe4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.449
_cell_length_b   7.449
_cell_length_c   14.217
_cell_angle_alpha   85.015
_cell_angle_beta   85.015
_cell_angle_gamma   119.326
_symmetry_Int_Tables_number   1
_cell_volume   677.514
_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  0.582  0.250  0.253  1.0
  Er  Er1  1  0.084  0.417  0.750  1.0
  Er  Er2  1  0.250  0.582  0.253  1.0
  Er  Er3  1  0.332  0.332  0.005  1.0
  Er  Er4  1  0.749  0.749  0.750  1.0
  Er  Er5  1  0.917  0.917  0.253  1.0
  Er  Er6  1  0.417  0.084  0.750  1.0
  Cu  Cu7  1  0.813  0.479  0.560  1.0
  Cu  Cu8  1  0.479  0.813  0.560  1.0
  Cu  Cu9  1  0.146  0.146  0.560  1.0
  Te  Te10  1  0.128  0.794  0.616  1.0
  Te  Te11  1  0.293  0.958  0.123  1.0
  Te  Te12  1  0.794  0.128  0.616  1.0
  Te  Te13  1  0.958  0.293  0.123  1.0
  Te  Te14  1  0.710  0.375  0.875  1.0
  Te  Te15  1  0.462  0.462  0.616  1.0
  Te  Te16  1  0.875  0.541  0.375  1.0
  Te  Te17  1  0.627  0.627  0.123  1.0
  Te  Te18  1  0.375  0.710  0.875  1.0
  Te  Te19  1  0.541  0.875  0.375  1.0
  Te  Te20  1  0.040  0.040  0.875  1.0
  Te  Te21  1  0.207  0.207  0.376  1.0
[/CIF]
.
The compound described by Er7Cu3Te12 is Corundum-derived structured and crystallizes in the monoclinic Cm space group. There are five inequivalent Er sites. In the first Er site, Er(1) is bonded to one Te(6), one Te(8), two equivalent Te(2), and two equivalent Te(5) atoms to form ErTe6 octahedra that share  a cornercorner with one Er(3)Te6 octahedra,  a cornercorner with one Cu(2)Te4 tetrahedra, corners with two equivalent Cu(1)Te4 tetrahedra,  an edgeedge with one Er(3)Te6 octahedra, edges with three equivalent Er(1)Te6 octahedra, and edges with three equivalent Er(5)Te6 octahedra. The corner-sharing octahedral tilt angles are 3°. In the second Er site, Er(2) is bonded to one Te(4), one Te(7), two equivalent Te(1), and two equivalent Te(3) atoms to form ErTe6 octahedra that share  a cornercorner with one Er(3)Te6 octahedra,  a cornercorner with one Cu(2)Te4 tetrahedra, corners with two equivalent Cu(1)Te4 tetrahedra,  an edgeedge with one Er(3)Te6 octahedra, edges with three equivalent Er(2)Te6 octahedra, edges with three equivalent Er(4)Te6 octahedra,  an edgeedge with one Cu(2)Te4 tetrahedra, and edges with two equivalent Cu(1)Te4 tetrahedra. The corner-sharing octahedral tilt angles are 1°. In the third Er site, Er(3) is bonded to one Te(6), one Te(7), two equivalent Te(2), and two equivalent Te(3) atoms to form a mixture of corner and edge-sharing ErTe6 octahedra. The corner-sharing octahedral tilt angles range from 1-3°. In the fourth Er site, Er(4) is bonded to one Te(4), one Te(7), two equivalent Te(1), and two equivalent Te(3) atoms to form ErTe6 octahedra that share  a cornercorner with one Er(3)Te6 octahedra,  a cornercorner with one Cu(2)Te4 tetrahedra, corners with two equivalent Cu(1)Te4 tetrahedra,  an edgeedge with one Er(3)Te6 octahedra, edges with six equivalent Er(2)Te6 octahedra,  an edgeedge with one Cu(2)Te4 tetrahedra, and edges with two equivalent Cu(1)Te4 tetrahedra. The corner-sharing octahedral tilt angles are 1°. In the fifth Er site, Er(5) is bonded to one Te(6), one Te(8), two equivalent Te(2), and two equivalent Te(5) atoms to form ErTe6 octahedra that share  a cornercorner with one Er(3)Te6 octahedra,  a cornercorner with one Cu(2)Te4 tetrahedra, corners with two equivalent Cu(1)Te4 tetrahedra,  an edgeedge with one Er(3)Te6 octahedra, and edges with six equivalent Er(1)Te6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Te(4), one Te(5), and two equivalent Te(1) atoms to form CuTe4 tetrahedra that share  a cornercorner with one Er(4)Te6 octahedra,  a cornercorner with one Er(5)Te6 octahedra, corners with two equivalent Er(1)Te6 octahedra, corners with two equivalent Er(2)Te6 octahedra, corners with three equivalent Cu(1)Te4 tetrahedra, corners with three equivalent Cu(2)Te4 tetrahedra,  an edgeedge with one Er(4)Te6 octahedra, and edges with two equivalent Er(2)Te6 octahedra. The corner-sharing octahedral tilt angles range from 19-56°. In the second Cu site, Cu(2) is bonded to one Te(4), one Te(8), and two equivalent Te(1) atoms to form CuTe4 tetrahedra that share  a cornercorner with one Er(4)Te6 octahedra,  a cornercorner with one Er(5)Te6 octahedra, corners with two equivalent Er(1)Te6 octahedra, corners with two equivalent Er(2)Te6 octahedra, corners with six equivalent Cu(1)Te4 tetrahedra,  an edgeedge with one Er(4)Te6 octahedra, and edges with two equivalent Er(2)Te6 octahedra. The corner-sharing octahedral tilt angles range from 19-55°. There are eight inequivalent Te sites. In the first Te site, Te(1) is bonded to one Er(4), two equivalent Er(2), one Cu(2), and two equivalent Cu(1) atoms to form distorted edge-sharing TeEr3Cu3 octahedra. In the second Te site, Te(2) is bonded in a rectangular see-saw-like geometry to one Er(3), one Er(5), and two equivalent Er(1) atoms. In the third Te site, Te(3) is bonded in a rectangular see-saw-like geometry to one Er(3), one Er(4), and two equivalent Er(2) atoms. In the fourth Te site, Te(4) is bonded to one Er(4), two equivalent Er(2), one Cu(2), and two equivalent Cu(1) atoms to form distorted edge-sharing TeEr3Cu3 octahedra. In the fifth Te site, Te(5) is bonded in a rectangular see-saw-like geometry to one Er(5), two equivalent Er(1), and one Cu(1) atom. In the sixth Te site, Te(6) is bonded in a rectangular see-saw-like geometry to one Er(3), one Er(5), and two equivalent Er(1) atoms. In the seventh Te site, Te(7) is bonded in a rectangular see-saw-like geometry to one Er(3), one Er(4), and two equivalent Er(2) atoms. In the eighth Te site, Te(8) is bonded in a rectangular see-saw-like geometry to one Er(5), two equivalent Er(1), and one Cu(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Er7(CuTe4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.449
_cell_length_b   7.449
_cell_length_c   14.217
_cell_angle_alpha   85.015
_cell_angle_beta   85.015
_cell_angle_gamma   119.326
_symmetry_Int_Tables_number   1
_cell_volume   677.514
_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  0.582  0.250  0.253  1.0
  Er  Er1  1  0.084  0.417  0.750  1.0
  Er  Er2  1  0.250  0.582  0.253  1.0
  Er  Er3  1  0.332  0.332  0.005  1.0
  Er  Er4  1  0.749  0.749  0.750  1.0
  Er  Er5  1  0.917  0.917  0.253  1.0
  Er  Er6  1  0.417  0.084  0.750  1.0
  Cu  Cu7  1  0.813  0.479  0.560  1.0
  Cu  Cu8  1  0.479  0.813  0.560  1.0
  Cu  Cu9  1  0.146  0.146  0.560  1.0
  Te  Te10  1  0.128  0.794  0.616  1.0
  Te  Te11  1  0.293  0.958  0.123  1.0
  Te  Te12  1  0.794  0.128  0.616  1.0
  Te  Te13  1  0.958  0.293  0.123  1.0
  Te  Te14  1  0.710  0.375  0.875  1.0
  Te  Te15  1  0.462  0.462  0.616  1.0
  Te  Te16  1  0.875  0.541  0.375  1.0
  Te  Te17  1  0.627  0.627  0.123  1.0
  Te  Te18  1  0.375  0.710  0.875  1.0
  Te  Te19  1  0.541  0.875  0.375  1.0
  Te  Te20  1  0.040  0.040  0.875  1.0
  Te  Te21  1  0.207  0.207  0.376  1.0
[/CIF]
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