The crystal structure described by MgTmSe3 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 Tm(1)Se6 octahedra, edges with three equivalent Mg(1)Se6 octahedra, and  a faceface with one Tm(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 42-56°. Tm(1) is bonded to six equivalent Se(1) atoms to form TmSe6 octahedra that share corners with nine equivalent Mg(1)Se6 octahedra, edges with three equivalent Tm(1)Se6 octahedra, and  a faceface with one Mg(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 42-56°. Se(1) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Tm(1) atoms. is represented by the CIF card [CIF]
data_TmMgSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.870
_cell_length_b   6.870
_cell_length_c   7.510
_cell_angle_alpha   62.781
_cell_angle_beta   62.781
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   260.649
_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
  Mg  Mg0  1  0.159  0.159  0.522  1.0
  Mg  Mg1  1  0.841  0.841  0.478  1.0
  Se  Se2  1  0.232  0.947  0.249  1.0
  Se  Se3  1  0.768  0.053  0.751  1.0
  Se  Se4  1  0.947  0.572  0.249  1.0
  Se  Se5  1  0.053  0.428  0.751  1.0
  Se  Se6  1  0.572  0.232  0.249  1.0
  Se  Se7  1  0.428  0.768  0.751  1.0
  Tm  Tm8  1  0.346  0.346  0.961  1.0
  Tm  Tm9  1  0.654  0.654  0.039  1.0
[/CIF]
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The crystal structure described by MgTmSe3 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 Tm(1)Se6 octahedra, edges with three equivalent Mg(1)Se6 octahedra, and  a faceface with one Tm(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 42-56°. Tm(1) is bonded to six equivalent Se(1) atoms to form TmSe6 octahedra that share corners with nine equivalent Mg(1)Se6 octahedra, edges with three equivalent Tm(1)Se6 octahedra, and  a faceface with one Mg(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 42-56°. Se(1) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Tm(1) atoms. is represented by the CIF card [CIF]
data_TmMgSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.870
_cell_length_b   6.870
_cell_length_c   7.510
_cell_angle_alpha   62.781
_cell_angle_beta   62.781
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   260.649
_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
  Mg  Mg0  1  0.159  0.159  0.522  1.0
  Mg  Mg1  1  0.841  0.841  0.478  1.0
  Se  Se2  1  0.232  0.947  0.249  1.0
  Se  Se3  1  0.768  0.053  0.751  1.0
  Se  Se4  1  0.947  0.572  0.249  1.0
  Se  Se5  1  0.053  0.428  0.751  1.0
  Se  Se6  1  0.572  0.232  0.249  1.0
  Se  Se7  1  0.428  0.768  0.751  1.0
  Tm  Tm8  1  0.346  0.346  0.961  1.0
  Tm  Tm9  1  0.654  0.654  0.039  1.0
[/CIF]
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