The structure described by MgErSe3 is Ilmenite structured and crystallizes in the trigonal R-3 space group. Mg(1) is bonded to six equivalent Se(1) atoms to form MgSe6 octahedra that share corners with nine equivalent Er(1)Se6 octahedra, edges with three equivalent Mg(1)Se6 octahedra, and  a faceface with one Er(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. Er(1) is bonded to six equivalent Se(1) atoms to form ErSe6 octahedra that share corners with nine equivalent Mg(1)Se6 octahedra, edges with three equivalent Er(1)Se6 octahedra, and  a faceface with one Mg(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. Se(1) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Er(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_ErMgSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.874
_cell_length_b   6.874
_cell_length_c   7.528
_cell_angle_alpha   62.835
_cell_angle_beta   62.835
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   261.719
_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  0.348  0.348  0.957  1.0
  Er  Er1  1  0.652  0.652  0.043  1.0
  Mg  Mg2  1  0.162  0.162  0.515  1.0
  Mg  Mg3  1  0.838  0.838  0.485  1.0
  Se  Se4  1  0.226  0.950  0.247  1.0
  Se  Se5  1  0.774  0.050  0.753  1.0
  Se  Se6  1  0.950  0.577  0.247  1.0
  Se  Se7  1  0.050  0.423  0.753  1.0
  Se  Se8  1  0.577  0.226  0.247  1.0
  Se  Se9  1  0.423  0.774  0.753  1.0
[/CIF]
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The structure described by MgErSe3 is Ilmenite structured and crystallizes in the trigonal R-3 space group. Mg(1) is bonded to six equivalent Se(1) atoms to form MgSe6 octahedra that share corners with nine equivalent Er(1)Se6 octahedra, edges with three equivalent Mg(1)Se6 octahedra, and  a faceface with one Er(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. Er(1) is bonded to six equivalent Se(1) atoms to form ErSe6 octahedra that share corners with nine equivalent Mg(1)Se6 octahedra, edges with three equivalent Er(1)Se6 octahedra, and  a faceface with one Mg(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. Se(1) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Er(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_ErMgSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.874
_cell_length_b   6.874
_cell_length_c   7.528
_cell_angle_alpha   62.835
_cell_angle_beta   62.835
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   261.719
_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  0.348  0.348  0.957  1.0
  Er  Er1  1  0.652  0.652  0.043  1.0
  Mg  Mg2  1  0.162  0.162  0.515  1.0
  Mg  Mg3  1  0.838  0.838  0.485  1.0
  Se  Se4  1  0.226  0.950  0.247  1.0
  Se  Se5  1  0.774  0.050  0.753  1.0
  Se  Se6  1  0.950  0.577  0.247  1.0
  Se  Se7  1  0.050  0.423  0.753  1.0
  Se  Se8  1  0.577  0.226  0.247  1.0
  Se  Se9  1  0.423  0.774  0.753  1.0
[/CIF]
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