The crystal structure described by MgTb2S4 crystallizes in the orthorhombic Cmc2_1 space group. Mg(1) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(3) atoms to form MgS6 octahedra that share corners with three equivalent Tb(2)S6 octahedra, corners with four equivalent Tb(1)S7 pentagonal bipyramids, edges with two equivalent Mg(1)S6 octahedra, edges with three equivalent Tb(2)S6 octahedra, and edges with three equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-54°. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to one S(2), two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form distorted TbS7 pentagonal bipyramids that share corners with four equivalent Mg(1)S6 octahedra, corners with four equivalent Tb(2)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, edges with three equivalent Tb(2)S6 octahedra, and faces with two equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 17-67°. In the second Tb site, Tb(2) is bonded to one S(3), one S(4), two equivalent S(1), and two equivalent S(2) atoms to form TbS6 octahedra that share corners with three equivalent Mg(1)S6 octahedra, corners with four equivalent Tb(1)S7 pentagonal bipyramids, edges with two equivalent Tb(2)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, and edges with three equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-54°. There are four inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1), two equivalent Tb(1), and two equivalent Tb(2) atoms to form distorted STb4Mg trigonal bipyramids that share corners with two equivalent S(3)Tb3Mg2 square pyramids, corners with six equivalent S(2)Tb3Mg2 square pyramids, corners with five equivalent S(4)Tb3Mg tetrahedra,  an edgeedge with one S(2)Tb3Mg2 square pyramid, edges with three equivalent S(3)Tb3Mg2 square pyramids,  an edgeedge with one S(4)Tb3Mg tetrahedra, and edges with two equivalent S(1)Tb4Mg trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent Mg(1), one Tb(1), and two equivalent Tb(2) atoms to form STb3Mg2 square pyramids that share corners with two equivalent S(3)Tb3Mg2 square pyramids, corners with two equivalent S(4)Tb3Mg tetrahedra, corners with six equivalent S(1)Tb4Mg trigonal bipyramids, edges with two equivalent S(2)Tb3Mg2 square pyramids, edges with three equivalent S(3)Tb3Mg2 square pyramids, edges with two equivalent S(4)Tb3Mg tetrahedra, and  an edgeedge with one S(1)Tb4Mg trigonal bipyramid. In the third S site, S(3) is bonded to two equivalent Mg(1), one Tb(2), and two equivalent Tb(1) atoms to form STb3Mg2 square pyramids that share corners with two equivalent S(2)Tb3Mg2 square pyramids, corners with five equivalent S(4)Tb3Mg tetrahedra, corners with two equivalent S(1)Tb4Mg trigonal bipyramids, edges with two equivalent S(3)Tb3Mg2 square pyramids, edges with three equivalent S(2)Tb3Mg2 square pyramids,  an edgeedge with one S(4)Tb3Mg tetrahedra, and edges with three equivalent S(1)Tb4Mg trigonal bipyramids. In the fourth S site, S(4) is bonded to one Mg(1), one Tb(2), and two equivalent Tb(1) atoms to form STb3Mg tetrahedra that share corners with two equivalent S(2)Tb3Mg2 square pyramids, corners with five equivalent S(3)Tb3Mg2 square pyramids, corners with two equivalent S(4)Tb3Mg tetrahedra, corners with five equivalent S(1)Tb4Mg trigonal bipyramids,  an edgeedge with one S(3)Tb3Mg2 square pyramid, edges with two equivalent S(2)Tb3Mg2 square pyramids, and  an edgeedge with one S(1)Tb4Mg trigonal bipyramid. is represented by the CIF card [CIF]
data_Tb2MgS4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.527
_cell_length_b   6.527
_cell_length_c   12.869
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   146.213
_symmetry_Int_Tables_number   1
_cell_volume   304.836
_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
  Tb  Tb0  1  0.382  0.618  0.784  1.0
  Tb  Tb1  1  0.618  0.382  0.284  1.0
  Tb  Tb2  1  0.138  0.862  0.583  1.0
  Tb  Tb3  1  0.862  0.138  0.083  1.0
  Mg  Mg4  1  0.126  0.874  0.946  1.0
  Mg  Mg5  1  0.874  0.126  0.446  1.0
  S  S6  1  0.790  0.210  0.635  1.0
  S  S7  1  0.210  0.790  0.135  1.0
  S  S8  1  0.488  0.512  0.996  1.0
  S  S9  1  0.512  0.488  0.496  1.0
  S  S10  1  0.761  0.239  0.896  1.0
  S  S11  1  0.239  0.761  0.396  1.0
  S  S12  1  0.037  0.963  0.769  1.0
  S  S13  1  0.963  0.037  0.269  1.0
[/CIF]
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The crystal structure described by MgTb2S4 crystallizes in the orthorhombic Cmc2_1 space group. Mg(1) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(3) atoms to form MgS6 octahedra that share corners with three equivalent Tb(2)S6 octahedra, corners with four equivalent Tb(1)S7 pentagonal bipyramids, edges with two equivalent Mg(1)S6 octahedra, edges with three equivalent Tb(2)S6 octahedra, and edges with three equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-54°. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to one S(2), two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form distorted TbS7 pentagonal bipyramids that share corners with four equivalent Mg(1)S6 octahedra, corners with four equivalent Tb(2)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, edges with three equivalent Tb(2)S6 octahedra, and faces with two equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 17-67°. In the second Tb site, Tb(2) is bonded to one S(3), one S(4), two equivalent S(1), and two equivalent S(2) atoms to form TbS6 octahedra that share corners with three equivalent Mg(1)S6 octahedra, corners with four equivalent Tb(1)S7 pentagonal bipyramids, edges with two equivalent Tb(2)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, and edges with three equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-54°. There are four inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1), two equivalent Tb(1), and two equivalent Tb(2) atoms to form distorted STb4Mg trigonal bipyramids that share corners with two equivalent S(3)Tb3Mg2 square pyramids, corners with six equivalent S(2)Tb3Mg2 square pyramids, corners with five equivalent S(4)Tb3Mg tetrahedra,  an edgeedge with one S(2)Tb3Mg2 square pyramid, edges with three equivalent S(3)Tb3Mg2 square pyramids,  an edgeedge with one S(4)Tb3Mg tetrahedra, and edges with two equivalent S(1)Tb4Mg trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent Mg(1), one Tb(1), and two equivalent Tb(2) atoms to form STb3Mg2 square pyramids that share corners with two equivalent S(3)Tb3Mg2 square pyramids, corners with two equivalent S(4)Tb3Mg tetrahedra, corners with six equivalent S(1)Tb4Mg trigonal bipyramids, edges with two equivalent S(2)Tb3Mg2 square pyramids, edges with three equivalent S(3)Tb3Mg2 square pyramids, edges with two equivalent S(4)Tb3Mg tetrahedra, and  an edgeedge with one S(1)Tb4Mg trigonal bipyramid. In the third S site, S(3) is bonded to two equivalent Mg(1), one Tb(2), and two equivalent Tb(1) atoms to form STb3Mg2 square pyramids that share corners with two equivalent S(2)Tb3Mg2 square pyramids, corners with five equivalent S(4)Tb3Mg tetrahedra, corners with two equivalent S(1)Tb4Mg trigonal bipyramids, edges with two equivalent S(3)Tb3Mg2 square pyramids, edges with three equivalent S(2)Tb3Mg2 square pyramids,  an edgeedge with one S(4)Tb3Mg tetrahedra, and edges with three equivalent S(1)Tb4Mg trigonal bipyramids. In the fourth S site, S(4) is bonded to one Mg(1), one Tb(2), and two equivalent Tb(1) atoms to form STb3Mg tetrahedra that share corners with two equivalent S(2)Tb3Mg2 square pyramids, corners with five equivalent S(3)Tb3Mg2 square pyramids, corners with two equivalent S(4)Tb3Mg tetrahedra, corners with five equivalent S(1)Tb4Mg trigonal bipyramids,  an edgeedge with one S(3)Tb3Mg2 square pyramid, edges with two equivalent S(2)Tb3Mg2 square pyramids, and  an edgeedge with one S(1)Tb4Mg trigonal bipyramid. is represented by the CIF card [CIF]
data_Tb2MgS4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.527
_cell_length_b   6.527
_cell_length_c   12.869
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   146.213
_symmetry_Int_Tables_number   1
_cell_volume   304.836
_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
  Tb  Tb0  1  0.382  0.618  0.784  1.0
  Tb  Tb1  1  0.618  0.382  0.284  1.0
  Tb  Tb2  1  0.138  0.862  0.583  1.0
  Tb  Tb3  1  0.862  0.138  0.083  1.0
  Mg  Mg4  1  0.126  0.874  0.946  1.0
  Mg  Mg5  1  0.874  0.126  0.446  1.0
  S  S6  1  0.790  0.210  0.635  1.0
  S  S7  1  0.210  0.790  0.135  1.0
  S  S8  1  0.488  0.512  0.996  1.0
  S  S9  1  0.512  0.488  0.496  1.0
  S  S10  1  0.761  0.239  0.896  1.0
  S  S11  1  0.239  0.761  0.396  1.0
  S  S12  1  0.037  0.963  0.769  1.0
  S  S13  1  0.963  0.037  0.269  1.0
[/CIF]
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