The compound described by MgTm2S4 crystallizes in the orthorhombic Pnma space group. Mg(1) is bonded to two equivalent S(4) and three equivalent S(1) atoms to form MgS5 square pyramids that share corners with two equivalent Tm(1)S6 octahedra, corners with two equivalent Tm(2)S6 octahedra,  an edgeedge with one Tm(1)S6 octahedra, edges with three equivalent Tm(2)S6 octahedra, and edges with four equivalent Mg(1)S5 square pyramids. The corner-sharing octahedral tilt angles range from 4-5°. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to one S(3), two equivalent S(4), and three equivalent S(2) atoms to form TmS6 octahedra that share corners with three equivalent Tm(2)S6 octahedra, corners with two equivalent Mg(1)S5 square pyramids, edges with two equivalent Tm(2)S6 octahedra, edges with four equivalent Tm(1)S6 octahedra, and  an edgeedge with one Mg(1)S5 square pyramid. The corner-sharing octahedral tilt angles range from 55-58°. In the second Tm site, Tm(2) is bonded to one S(2), one S(4), two equivalent S(1), and two equivalent S(3) atoms to form TmS6 octahedra that share corners with three equivalent Tm(1)S6 octahedra, corners with two equivalent Mg(1)S5 square pyramids, edges with two equivalent Tm(1)S6 octahedra, edges with two equivalent Tm(2)S6 octahedra, and edges with three equivalent Mg(1)S5 square pyramids. The corner-sharing octahedral tilt angles range from 55-58°. There are four inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Mg(1) and two equivalent Tm(2) atoms to form STm2Mg3 square pyramids that share corners with two equivalent S(4)Tm3Mg2 square pyramids, edges with three equivalent S(4)Tm3Mg2 square pyramids, and edges with four equivalent S(1)Tm2Mg3 square pyramids. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Tm(2) and three equivalent Tm(1) atoms. In the third S site, S(3) is bonded in a distorted T-shaped geometry to one Tm(1) and two equivalent Tm(2) atoms. In the fourth S site, S(4) is bonded to two equivalent Mg(1), one Tm(2), and two equivalent Tm(1) atoms to form STm3Mg2 square pyramids that share corners with two equivalent S(1)Tm2Mg3 square pyramids, edges with two equivalent S(4)Tm3Mg2 square pyramids, and edges with three equivalent S(1)Tm2Mg3 square pyramids. is represented by the CIF file [CIF]
data_Tm2MgS4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.484
_cell_length_b   3.805
_cell_length_c   13.329
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   633.122
_cell_formula_units_Z   4
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  0.117  0.250  0.074  1.0
  Tm  Tm1  1  0.883  0.750  0.926  1.0
  Tm  Tm2  1  0.383  0.750  0.574  1.0
  Tm  Tm3  1  0.617  0.250  0.426  1.0
  Tm  Tm4  1  0.139  0.250  0.704  1.0
  Tm  Tm5  1  0.861  0.750  0.296  1.0
  Tm  Tm6  1  0.361  0.750  0.204  1.0
  Tm  Tm7  1  0.639  0.250  0.796  1.0
  Mg  Mg8  1  0.112  0.750  0.452  1.0
  Mg  Mg9  1  0.888  0.250  0.548  1.0
  Mg  Mg10  1  0.388  0.250  0.952  1.0
  Mg  Mg11  1  0.612  0.750  0.048  1.0
  S  S12  1  0.009  0.750  0.617  1.0
  S  S13  1  0.991  0.250  0.383  1.0
  S  S14  1  0.491  0.250  0.117  1.0
  S  S15  1  0.509  0.750  0.883  1.0
  S  S16  1  0.027  0.250  0.883  1.0
  S  S17  1  0.973  0.750  0.117  1.0
  S  S18  1  0.473  0.750  0.383  1.0
  S  S19  1  0.527  0.250  0.617  1.0
  S  S20  1  0.225  0.250  0.246  1.0
  S  S21  1  0.775  0.750  0.754  1.0
  S  S22  1  0.275  0.750  0.746  1.0
  S  S23  1  0.725  0.250  0.254  1.0
  S  S24  1  0.261  0.750  0.016  1.0
  S  S25  1  0.739  0.250  0.984  1.0
  S  S26  1  0.239  0.250  0.516  1.0
  S  S27  1  0.761  0.750  0.484  1.0
[/CIF]
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The compound described by MgTm2S4 crystallizes in the orthorhombic Pnma space group. Mg(1) is bonded to two equivalent S(4) and three equivalent S(1) atoms to form MgS5 square pyramids that share corners with two equivalent Tm(1)S6 octahedra, corners with two equivalent Tm(2)S6 octahedra,  an edgeedge with one Tm(1)S6 octahedra, edges with three equivalent Tm(2)S6 octahedra, and edges with four equivalent Mg(1)S5 square pyramids. The corner-sharing octahedral tilt angles range from 4-5°. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to one S(3), two equivalent S(4), and three equivalent S(2) atoms to form TmS6 octahedra that share corners with three equivalent Tm(2)S6 octahedra, corners with two equivalent Mg(1)S5 square pyramids, edges with two equivalent Tm(2)S6 octahedra, edges with four equivalent Tm(1)S6 octahedra, and  an edgeedge with one Mg(1)S5 square pyramid. The corner-sharing octahedral tilt angles range from 55-58°. In the second Tm site, Tm(2) is bonded to one S(2), one S(4), two equivalent S(1), and two equivalent S(3) atoms to form TmS6 octahedra that share corners with three equivalent Tm(1)S6 octahedra, corners with two equivalent Mg(1)S5 square pyramids, edges with two equivalent Tm(1)S6 octahedra, edges with two equivalent Tm(2)S6 octahedra, and edges with three equivalent Mg(1)S5 square pyramids. The corner-sharing octahedral tilt angles range from 55-58°. There are four inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Mg(1) and two equivalent Tm(2) atoms to form STm2Mg3 square pyramids that share corners with two equivalent S(4)Tm3Mg2 square pyramids, edges with three equivalent S(4)Tm3Mg2 square pyramids, and edges with four equivalent S(1)Tm2Mg3 square pyramids. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Tm(2) and three equivalent Tm(1) atoms. In the third S site, S(3) is bonded in a distorted T-shaped geometry to one Tm(1) and two equivalent Tm(2) atoms. In the fourth S site, S(4) is bonded to two equivalent Mg(1), one Tm(2), and two equivalent Tm(1) atoms to form STm3Mg2 square pyramids that share corners with two equivalent S(1)Tm2Mg3 square pyramids, edges with two equivalent S(4)Tm3Mg2 square pyramids, and edges with three equivalent S(1)Tm2Mg3 square pyramids. is represented by the CIF file [CIF]
data_Tm2MgS4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.484
_cell_length_b   3.805
_cell_length_c   13.329
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   633.122
_cell_formula_units_Z   4
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  0.117  0.250  0.074  1.0
  Tm  Tm1  1  0.883  0.750  0.926  1.0
  Tm  Tm2  1  0.383  0.750  0.574  1.0
  Tm  Tm3  1  0.617  0.250  0.426  1.0
  Tm  Tm4  1  0.139  0.250  0.704  1.0
  Tm  Tm5  1  0.861  0.750  0.296  1.0
  Tm  Tm6  1  0.361  0.750  0.204  1.0
  Tm  Tm7  1  0.639  0.250  0.796  1.0
  Mg  Mg8  1  0.112  0.750  0.452  1.0
  Mg  Mg9  1  0.888  0.250  0.548  1.0
  Mg  Mg10  1  0.388  0.250  0.952  1.0
  Mg  Mg11  1  0.612  0.750  0.048  1.0
  S  S12  1  0.009  0.750  0.617  1.0
  S  S13  1  0.991  0.250  0.383  1.0
  S  S14  1  0.491  0.250  0.117  1.0
  S  S15  1  0.509  0.750  0.883  1.0
  S  S16  1  0.027  0.250  0.883  1.0
  S  S17  1  0.973  0.750  0.117  1.0
  S  S18  1  0.473  0.750  0.383  1.0
  S  S19  1  0.527  0.250  0.617  1.0
  S  S20  1  0.225  0.250  0.246  1.0
  S  S21  1  0.775  0.750  0.754  1.0
  S  S22  1  0.275  0.750  0.746  1.0
  S  S23  1  0.725  0.250  0.254  1.0
  S  S24  1  0.261  0.750  0.016  1.0
  S  S25  1  0.739  0.250  0.984  1.0
  S  S26  1  0.239  0.250  0.516  1.0
  S  S27  1  0.761  0.750  0.484  1.0
[/CIF]
.