The material described by Ti4FeSe8 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form TiSe6 octahedra that share corners with four equivalent Fe(1)Se6 octahedra, edges with two equivalent Ti(1)Se6 octahedra, and edges with four equivalent Ti(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-50°. In the second Ti site, Ti(2) is bonded to one Se(1), one Se(3), and four equivalent Se(2) atoms to form TiSe6 octahedra that share corners with two equivalent Fe(1)Se6 octahedra, edges with two equivalent Ti(2)Se6 octahedra, edges with four equivalent Ti(1)Se6 octahedra, and  a faceface with one Fe(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 49°. Fe(1) is bonded to two equivalent Se(3) and four equivalent Se(2) atoms to form FeSe6 octahedra that share corners with four equivalent Ti(2)Se6 octahedra, corners with eight equivalent Ti(1)Se6 octahedra, and faces with two equivalent Ti(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-50°. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted T-shaped geometry to one Ti(2) and two equivalent Ti(1) atoms. In the second Se site, Se(2) is bonded in a rectangular see-saw-like geometry to one Ti(1), two equivalent Ti(2), and one Fe(1) atom. In the third Se site, Se(3) is bonded in a rectangular see-saw-like geometry to one Ti(2), two equivalent Ti(1), and one Fe(1) atom. is represented by the CIF card [CIF]
data_Ti4FeSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.986
_cell_length_b   6.986
_cell_length_c   8.580
_cell_angle_alpha   53.166
_cell_angle_beta   53.166
_cell_angle_gamma   61.247
_symmetry_Int_Tables_number   1
_cell_volume   263.379
_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
  Ti  Ti0  1  0.738  0.262  0.500  1.0
  Ti  Ti1  1  0.262  0.738  0.500  1.0
  Ti  Ti2  1  0.746  0.746  0.010  1.0
  Ti  Ti3  1  0.254  0.254  0.990  1.0
  Fe  Fe4  1  0.000  0.000  0.000  1.0
  Se  Se5  1  0.453  0.453  0.331  1.0
  Se  Se6  1  0.547  0.547  0.669  1.0
  Se  Se7  1  0.544  0.048  0.169  1.0
  Se  Se8  1  0.456  0.952  0.831  1.0
  Se  Se9  1  0.952  0.456  0.831  1.0
  Se  Se10  1  0.048  0.544  0.169  1.0
  Se  Se11  1  0.956  0.956  0.335  1.0
  Se  Se12  1  0.044  0.044  0.665  1.0
[/CIF]
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The material described by Ti4FeSe8 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form TiSe6 octahedra that share corners with four equivalent Fe(1)Se6 octahedra, edges with two equivalent Ti(1)Se6 octahedra, and edges with four equivalent Ti(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-50°. In the second Ti site, Ti(2) is bonded to one Se(1), one Se(3), and four equivalent Se(2) atoms to form TiSe6 octahedra that share corners with two equivalent Fe(1)Se6 octahedra, edges with two equivalent Ti(2)Se6 octahedra, edges with four equivalent Ti(1)Se6 octahedra, and  a faceface with one Fe(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 49°. Fe(1) is bonded to two equivalent Se(3) and four equivalent Se(2) atoms to form FeSe6 octahedra that share corners with four equivalent Ti(2)Se6 octahedra, corners with eight equivalent Ti(1)Se6 octahedra, and faces with two equivalent Ti(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-50°. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted T-shaped geometry to one Ti(2) and two equivalent Ti(1) atoms. In the second Se site, Se(2) is bonded in a rectangular see-saw-like geometry to one Ti(1), two equivalent Ti(2), and one Fe(1) atom. In the third Se site, Se(3) is bonded in a rectangular see-saw-like geometry to one Ti(2), two equivalent Ti(1), and one Fe(1) atom. is represented by the CIF card [CIF]
data_Ti4FeSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.986
_cell_length_b   6.986
_cell_length_c   8.580
_cell_angle_alpha   53.166
_cell_angle_beta   53.166
_cell_angle_gamma   61.247
_symmetry_Int_Tables_number   1
_cell_volume   263.379
_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
  Ti  Ti0  1  0.738  0.262  0.500  1.0
  Ti  Ti1  1  0.262  0.738  0.500  1.0
  Ti  Ti2  1  0.746  0.746  0.010  1.0
  Ti  Ti3  1  0.254  0.254  0.990  1.0
  Fe  Fe4  1  0.000  0.000  0.000  1.0
  Se  Se5  1  0.453  0.453  0.331  1.0
  Se  Se6  1  0.547  0.547  0.669  1.0
  Se  Se7  1  0.544  0.048  0.169  1.0
  Se  Se8  1  0.456  0.952  0.831  1.0
  Se  Se9  1  0.952  0.456  0.831  1.0
  Se  Se10  1  0.048  0.544  0.169  1.0
  Se  Se11  1  0.956  0.956  0.335  1.0
  Se  Se12  1  0.044  0.044  0.665  1.0
[/CIF]
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