The structure described by TbCuMg4 crystallizes in the orthorhombic Cmmm space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted single-bond geometry to two equivalent Mg(2) and one Cu(1) atom. In the second Mg site, Mg(2) is bonded in a 11-coordinate geometry to one Mg(6), two equivalent Mg(4), four equivalent Mg(1), and four equivalent Mg(3) atoms. In the third Mg site, Mg(3) is bonded in a distorted single-bond geometry to two equivalent Mg(2), two equivalent Mg(6), and one Cu(1) atom. In the fourth Mg site, Mg(4) is bonded in an L-shaped geometry to one Mg(2) and two equivalent Cu(1) atoms. In the fifth Mg site, Mg(5) is bonded to four equivalent Tb(1), four equivalent Tb(2), and four equivalent Cu(1) atoms to form face-sharing MgTb8Cu4 cuboctahedra. In the sixth Mg site, Mg(6) is bonded in a 10-coordinate geometry to two equivalent Mg(2) and eight equivalent Mg(3) atoms. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 4-coordinate geometry to two equivalent Mg(5) and four equivalent Cu(1) atoms. In the second Tb site, Tb(2) is bonded in a 4-coordinate geometry to two equivalent Mg(5) and four equivalent Cu(1) atoms. Cu(1) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(3), one Mg(5), two equivalent Mg(4), two equivalent Tb(1), and two equivalent Tb(2) atoms. is represented by the CIF file [CIF]
data_TbMg4Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.096
_cell_length_b   12.096
_cell_length_c   3.892
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   112.471
_symmetry_Int_Tables_number   1
_cell_volume   526.262
_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
  Tb  Tb0  1  0.301  0.301  0.000  1.0
  Tb  Tb1  1  0.699  0.699  0.000  1.0
  Tb  Tb2  1  0.368  0.632  0.000  1.0
  Tb  Tb3  1  0.632  0.368  0.000  1.0
  Mg  Mg4  1  0.375  0.863  0.500  1.0
  Mg  Mg5  1  0.137  0.625  0.500  1.0
  Mg  Mg6  1  0.165  0.835  0.000  1.0
  Mg  Mg7  1  0.835  0.165  0.000  1.0
  Mg  Mg8  1  0.949  0.789  0.500  1.0
  Mg  Mg9  1  0.863  0.375  0.500  1.0
  Mg  Mg10  1  0.924  0.586  0.000  1.0
  Mg  Mg11  1  0.211  0.051  0.500  1.0
  Mg  Mg12  1  0.625  0.137  0.500  1.0
  Mg  Mg13  1  0.500  0.500  0.500  1.0
  Mg  Mg14  1  0.789  0.949  0.500  1.0
  Mg  Mg15  1  0.051  0.211  0.500  1.0
  Mg  Mg16  1  0.586  0.924  0.000  1.0
  Mg  Mg17  1  0.414  0.076  0.000  1.0
  Mg  Mg18  1  0.076  0.414  0.000  1.0
  Mg  Mg19  1  0.000  0.000  0.000  1.0
  Cu  Cu20  1  0.446  0.236  0.500  1.0
  Cu  Cu21  1  0.236  0.446  0.500  1.0
  Cu  Cu22  1  0.554  0.764  0.500  1.0
  Cu  Cu23  1  0.764  0.554  0.500  1.0
[/CIF]
.
The structure described by TbCuMg4 crystallizes in the orthorhombic Cmmm space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted single-bond geometry to two equivalent Mg(2) and one Cu(1) atom. In the second Mg site, Mg(2) is bonded in a 11-coordinate geometry to one Mg(6), two equivalent Mg(4), four equivalent Mg(1), and four equivalent Mg(3) atoms. In the third Mg site, Mg(3) is bonded in a distorted single-bond geometry to two equivalent Mg(2), two equivalent Mg(6), and one Cu(1) atom. In the fourth Mg site, Mg(4) is bonded in an L-shaped geometry to one Mg(2) and two equivalent Cu(1) atoms. In the fifth Mg site, Mg(5) is bonded to four equivalent Tb(1), four equivalent Tb(2), and four equivalent Cu(1) atoms to form face-sharing MgTb8Cu4 cuboctahedra. In the sixth Mg site, Mg(6) is bonded in a 10-coordinate geometry to two equivalent Mg(2) and eight equivalent Mg(3) atoms. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 4-coordinate geometry to two equivalent Mg(5) and four equivalent Cu(1) atoms. In the second Tb site, Tb(2) is bonded in a 4-coordinate geometry to two equivalent Mg(5) and four equivalent Cu(1) atoms. Cu(1) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(3), one Mg(5), two equivalent Mg(4), two equivalent Tb(1), and two equivalent Tb(2) atoms. is represented by the CIF file [CIF]
data_TbMg4Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.096
_cell_length_b   12.096
_cell_length_c   3.892
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   112.471
_symmetry_Int_Tables_number   1
_cell_volume   526.262
_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
  Tb  Tb0  1  0.301  0.301  0.000  1.0
  Tb  Tb1  1  0.699  0.699  0.000  1.0
  Tb  Tb2  1  0.368  0.632  0.000  1.0
  Tb  Tb3  1  0.632  0.368  0.000  1.0
  Mg  Mg4  1  0.375  0.863  0.500  1.0
  Mg  Mg5  1  0.137  0.625  0.500  1.0
  Mg  Mg6  1  0.165  0.835  0.000  1.0
  Mg  Mg7  1  0.835  0.165  0.000  1.0
  Mg  Mg8  1  0.949  0.789  0.500  1.0
  Mg  Mg9  1  0.863  0.375  0.500  1.0
  Mg  Mg10  1  0.924  0.586  0.000  1.0
  Mg  Mg11  1  0.211  0.051  0.500  1.0
  Mg  Mg12  1  0.625  0.137  0.500  1.0
  Mg  Mg13  1  0.500  0.500  0.500  1.0
  Mg  Mg14  1  0.789  0.949  0.500  1.0
  Mg  Mg15  1  0.051  0.211  0.500  1.0
  Mg  Mg16  1  0.586  0.924  0.000  1.0
  Mg  Mg17  1  0.414  0.076  0.000  1.0
  Mg  Mg18  1  0.076  0.414  0.000  1.0
  Mg  Mg19  1  0.000  0.000  0.000  1.0
  Cu  Cu20  1  0.446  0.236  0.500  1.0
  Cu  Cu21  1  0.236  0.446  0.500  1.0
  Cu  Cu22  1  0.554  0.764  0.500  1.0
  Cu  Cu23  1  0.764  0.554  0.500  1.0
[/CIF]
.