The material structure described by Tm2Fe15Si2 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 18-coordinate geometry to six equivalent Fe(2) and twelve equivalent Fe(3) atoms. In the second Tm site, Tm(2) is bonded in a 20-coordinate geometry to six equivalent Fe(1), six equivalent Fe(2), six equivalent Fe(3), and two equivalent Si(1) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Tm(2), four equivalent Fe(2), four equivalent Fe(3), and two equivalent Si(1) atoms to form distorted FeTm2Fe8Si2 cuboctahedra that share corners with four equivalent Fe(1)Tm2Fe8Si2 cuboctahedra, corners with ten equivalent Fe(3)Tm3Fe8Si cuboctahedra, edges with six equivalent Fe(3)Tm3Fe8Si cuboctahedra, faces with four equivalent Fe(3)Tm3Fe8Si cuboctahedra, and faces with six equivalent Fe(1)Tm2Fe8Si2 cuboctahedra. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to one Tm(1), one Tm(2), two equivalent Fe(1), two equivalent Fe(2), four equivalent Fe(3), and two equivalent Si(1) atoms. In the third Fe site, Fe(3) is bonded to one Tm(2), two equivalent Tm(1), two equivalent Fe(1), two equivalent Fe(3), four equivalent Fe(2), and one Si(1) atom to form distorted FeTm3Fe8Si cuboctahedra that share corners with five equivalent Fe(1)Tm2Fe8Si2 cuboctahedra, corners with ten equivalent Fe(3)Tm3Fe8Si cuboctahedra, edges with three equivalent Fe(1)Tm2Fe8Si2 cuboctahedra, edges with five equivalent Fe(3)Tm3Fe8Si cuboctahedra, faces with two equivalent Fe(1)Tm2Fe8Si2 cuboctahedra, and faces with eight equivalent Fe(3)Tm3Fe8Si cuboctahedra. Si(1) is bonded in a 14-coordinate geometry to one Tm(2), three equivalent Fe(1), three equivalent Fe(3), six equivalent Fe(2), and one Si(1) atom. is represented by the CIF file [CIF]
data_Tm2Fe15Si2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.296
_cell_length_b   8.296
_cell_length_c   8.334
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   496.754
_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
  Tm  Tm0  1  0.000  0.000  0.250  1.0
  Tm  Tm1  1  0.000  0.000  0.750  1.0
  Tm  Tm2  1  0.333  0.667  0.750  1.0
  Tm  Tm3  1  0.667  0.333  0.250  1.0
  Fe  Fe4  1  0.500  0.500  0.500  1.0
  Fe  Fe5  1  0.500  0.000  0.500  1.0
  Fe  Fe6  1  0.000  0.500  0.500  1.0
  Fe  Fe7  1  0.500  0.500  0.000  1.0
  Fe  Fe8  1  0.500  0.000  0.000  1.0
  Fe  Fe9  1  0.000  0.500  0.000  1.0
  Fe  Fe10  1  0.331  0.360  0.250  1.0
  Fe  Fe11  1  0.640  0.971  0.250  1.0
  Fe  Fe12  1  0.029  0.669  0.250  1.0
  Fe  Fe13  1  0.640  0.669  0.250  1.0
  Fe  Fe14  1  0.029  0.360  0.250  1.0
  Fe  Fe15  1  0.331  0.971  0.250  1.0
  Fe  Fe16  1  0.669  0.640  0.750  1.0
  Fe  Fe17  1  0.360  0.029  0.750  1.0
  Fe  Fe18  1  0.971  0.331  0.750  1.0
  Fe  Fe19  1  0.360  0.331  0.750  1.0
  Fe  Fe20  1  0.971  0.640  0.750  1.0
  Fe  Fe21  1  0.669  0.029  0.750  1.0
  Fe  Fe22  1  0.167  0.833  0.511  1.0
  Fe  Fe23  1  0.167  0.333  0.511  1.0
  Fe  Fe24  1  0.667  0.833  0.511  1.0
  Fe  Fe25  1  0.833  0.167  0.489  1.0
  Fe  Fe26  1  0.833  0.667  0.489  1.0
  Fe  Fe27  1  0.333  0.167  0.489  1.0
  Fe  Fe28  1  0.833  0.167  0.011  1.0
  Fe  Fe29  1  0.833  0.667  0.011  1.0
  Fe  Fe30  1  0.333  0.167  0.011  1.0
  Fe  Fe31  1  0.167  0.833  0.989  1.0
  Fe  Fe32  1  0.167  0.333  0.989  1.0
  Fe  Fe33  1  0.667  0.833  0.989  1.0
  Si  Si34  1  0.333  0.667  0.398  1.0
  Si  Si35  1  0.667  0.333  0.602  1.0
  Si  Si36  1  0.667  0.333  0.898  1.0
  Si  Si37  1  0.333  0.667  0.102  1.0
[/CIF]
.
The material structure described by Tm2Fe15Si2 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 18-coordinate geometry to six equivalent Fe(2) and twelve equivalent Fe(3) atoms. In the second Tm site, Tm(2) is bonded in a 20-coordinate geometry to six equivalent Fe(1), six equivalent Fe(2), six equivalent Fe(3), and two equivalent Si(1) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Tm(2), four equivalent Fe(2), four equivalent Fe(3), and two equivalent Si(1) atoms to form distorted FeTm2Fe8Si2 cuboctahedra that share corners with four equivalent Fe(1)Tm2Fe8Si2 cuboctahedra, corners with ten equivalent Fe(3)Tm3Fe8Si cuboctahedra, edges with six equivalent Fe(3)Tm3Fe8Si cuboctahedra, faces with four equivalent Fe(3)Tm3Fe8Si cuboctahedra, and faces with six equivalent Fe(1)Tm2Fe8Si2 cuboctahedra. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to one Tm(1), one Tm(2), two equivalent Fe(1), two equivalent Fe(2), four equivalent Fe(3), and two equivalent Si(1) atoms. In the third Fe site, Fe(3) is bonded to one Tm(2), two equivalent Tm(1), two equivalent Fe(1), two equivalent Fe(3), four equivalent Fe(2), and one Si(1) atom to form distorted FeTm3Fe8Si cuboctahedra that share corners with five equivalent Fe(1)Tm2Fe8Si2 cuboctahedra, corners with ten equivalent Fe(3)Tm3Fe8Si cuboctahedra, edges with three equivalent Fe(1)Tm2Fe8Si2 cuboctahedra, edges with five equivalent Fe(3)Tm3Fe8Si cuboctahedra, faces with two equivalent Fe(1)Tm2Fe8Si2 cuboctahedra, and faces with eight equivalent Fe(3)Tm3Fe8Si cuboctahedra. Si(1) is bonded in a 14-coordinate geometry to one Tm(2), three equivalent Fe(1), three equivalent Fe(3), six equivalent Fe(2), and one Si(1) atom. is represented by the CIF file [CIF]
data_Tm2Fe15Si2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.296
_cell_length_b   8.296
_cell_length_c   8.334
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   496.754
_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
  Tm  Tm0  1  0.000  0.000  0.250  1.0
  Tm  Tm1  1  0.000  0.000  0.750  1.0
  Tm  Tm2  1  0.333  0.667  0.750  1.0
  Tm  Tm3  1  0.667  0.333  0.250  1.0
  Fe  Fe4  1  0.500  0.500  0.500  1.0
  Fe  Fe5  1  0.500  0.000  0.500  1.0
  Fe  Fe6  1  0.000  0.500  0.500  1.0
  Fe  Fe7  1  0.500  0.500  0.000  1.0
  Fe  Fe8  1  0.500  0.000  0.000  1.0
  Fe  Fe9  1  0.000  0.500  0.000  1.0
  Fe  Fe10  1  0.331  0.360  0.250  1.0
  Fe  Fe11  1  0.640  0.971  0.250  1.0
  Fe  Fe12  1  0.029  0.669  0.250  1.0
  Fe  Fe13  1  0.640  0.669  0.250  1.0
  Fe  Fe14  1  0.029  0.360  0.250  1.0
  Fe  Fe15  1  0.331  0.971  0.250  1.0
  Fe  Fe16  1  0.669  0.640  0.750  1.0
  Fe  Fe17  1  0.360  0.029  0.750  1.0
  Fe  Fe18  1  0.971  0.331  0.750  1.0
  Fe  Fe19  1  0.360  0.331  0.750  1.0
  Fe  Fe20  1  0.971  0.640  0.750  1.0
  Fe  Fe21  1  0.669  0.029  0.750  1.0
  Fe  Fe22  1  0.167  0.833  0.511  1.0
  Fe  Fe23  1  0.167  0.333  0.511  1.0
  Fe  Fe24  1  0.667  0.833  0.511  1.0
  Fe  Fe25  1  0.833  0.167  0.489  1.0
  Fe  Fe26  1  0.833  0.667  0.489  1.0
  Fe  Fe27  1  0.333  0.167  0.489  1.0
  Fe  Fe28  1  0.833  0.167  0.011  1.0
  Fe  Fe29  1  0.833  0.667  0.011  1.0
  Fe  Fe30  1  0.333  0.167  0.011  1.0
  Fe  Fe31  1  0.167  0.833  0.989  1.0
  Fe  Fe32  1  0.167  0.333  0.989  1.0
  Fe  Fe33  1  0.667  0.833  0.989  1.0
  Si  Si34  1  0.333  0.667  0.398  1.0
  Si  Si35  1  0.667  0.333  0.602  1.0
  Si  Si36  1  0.667  0.333  0.898  1.0
  Si  Si37  1  0.333  0.667  0.102  1.0
[/CIF]
.