The crystal structure described by MgTb2Cu(GeO3)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(5), one O(7), and one O(9) atom. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), and one O(9) atom. In the second Tb site, Tb(2) is bonded to one O(1), one O(11), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form distorted TbO7 pentagonal bipyramids that share corners with two equivalent Ge(2)O4 tetrahedra, corners with two equivalent Ge(4)O4 tetrahedra, and  an edgeedge with one Ge(3)O4 tetrahedra. Cu(1) is bonded in a distorted T-shaped geometry to one O(10), one O(11), and one O(8) atom. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(11), one O(5), and one O(7) atom. In the second Ge site, Ge(2) is bonded to one O(10), one O(12), one O(2), and one O(6) atom to form GeO4 tetrahedra that share corners with two equivalent Tb(2)O7 pentagonal bipyramids,  a cornercorner with one Ge(3)O4 tetrahedra, and  a cornercorner with one Ge(4)O4 tetrahedra. In the third Ge site, Ge(3) is bonded to one O(3), one O(6), one O(7), and one O(9) atom to form GeO4 tetrahedra that share  a cornercorner with one Ge(2)O4 tetrahedra and  an edgeedge with one Tb(2)O7 pentagonal bipyramid. In the fourth Ge site, Ge(4) is bonded to one O(12), one O(4), one O(5), and one O(8) atom to form GeO4 tetrahedra that share corners with two equivalent Tb(2)O7 pentagonal bipyramids and  a cornercorner with one Ge(2)O4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted tetrahedral geometry to one Mg(1), one Tb(1), one Tb(2), and one Ge(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Tb(1), one Tb(2), and one Ge(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Tb(1), one Tb(2), and one Ge(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Tb(1), one Tb(2), and one Ge(4) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Tb(1), one Ge(1), and one Ge(4) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Tb(2), one Ge(2), and one Ge(3) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ge(1), and one Ge(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Tb(2), one Cu(1), and one Ge(4) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Mg(1), one Tb(1), and one Ge(3) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Tb(1), one Cu(1), and one Ge(2) atom. In the eleventh O site, O(11) is bonded in a distorted see-saw-like geometry to one Mg(1), one Tb(2), one Cu(1), and one Ge(1) atom. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Ge(2) and one Ge(4) atom. is represented by the CIF card [CIF]
data_Tb2MgCu(GeO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.368
_cell_length_b   7.310
_cell_length_c   7.652
_cell_angle_alpha   68.325
_cell_angle_beta   88.818
_cell_angle_gamma   79.498
_symmetry_Int_Tables_number   1
_cell_volume   273.998
_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
  Tb  Tb0  1  0.049  0.766  0.424  1.0
  Tb  Tb1  1  0.974  0.221  0.558  1.0
  Mg  Mg2  1  0.092  0.727  0.920  1.0
  Cu  Cu3  1  0.962  0.068  0.004  1.0
  Ge  Ge4  1  0.549  0.873  0.765  1.0
  Ge  Ge5  1  0.472  0.156  0.226  1.0
  Ge  Ge6  1  0.591  0.579  0.219  1.0
  Ge  Ge7  1  0.426  0.406  0.779  1.0
  O  O8  1  0.862  0.875  0.647  1.0
  O  O9  1  0.241  0.060  0.381  1.0
  O  O10  1  0.776  0.570  0.407  1.0
  O  O11  1  0.213  0.429  0.598  1.0
  O  O12  1  0.375  0.674  0.735  1.0
  O  O13  1  0.639  0.305  0.308  1.0
  O  O14  1  0.736  0.678  0.997  1.0
  O  O15  1  0.720  0.263  0.781  1.0
  O  O16  1  0.265  0.675  0.185  1.0
  O  O17  1  0.732  0.981  0.205  1.0
  O  O18  1  0.201  0.003  0.834  1.0
  O  O19  1  0.299  0.330  0.011  1.0
[/CIF]
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The crystal structure described by MgTb2Cu(GeO3)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(5), one O(7), and one O(9) atom. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), and one O(9) atom. In the second Tb site, Tb(2) is bonded to one O(1), one O(11), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form distorted TbO7 pentagonal bipyramids that share corners with two equivalent Ge(2)O4 tetrahedra, corners with two equivalent Ge(4)O4 tetrahedra, and  an edgeedge with one Ge(3)O4 tetrahedra. Cu(1) is bonded in a distorted T-shaped geometry to one O(10), one O(11), and one O(8) atom. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(11), one O(5), and one O(7) atom. In the second Ge site, Ge(2) is bonded to one O(10), one O(12), one O(2), and one O(6) atom to form GeO4 tetrahedra that share corners with two equivalent Tb(2)O7 pentagonal bipyramids,  a cornercorner with one Ge(3)O4 tetrahedra, and  a cornercorner with one Ge(4)O4 tetrahedra. In the third Ge site, Ge(3) is bonded to one O(3), one O(6), one O(7), and one O(9) atom to form GeO4 tetrahedra that share  a cornercorner with one Ge(2)O4 tetrahedra and  an edgeedge with one Tb(2)O7 pentagonal bipyramid. In the fourth Ge site, Ge(4) is bonded to one O(12), one O(4), one O(5), and one O(8) atom to form GeO4 tetrahedra that share corners with two equivalent Tb(2)O7 pentagonal bipyramids and  a cornercorner with one Ge(2)O4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted tetrahedral geometry to one Mg(1), one Tb(1), one Tb(2), and one Ge(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Tb(1), one Tb(2), and one Ge(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Tb(1), one Tb(2), and one Ge(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Tb(1), one Tb(2), and one Ge(4) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Tb(1), one Ge(1), and one Ge(4) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Tb(2), one Ge(2), and one Ge(3) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ge(1), and one Ge(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Tb(2), one Cu(1), and one Ge(4) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Mg(1), one Tb(1), and one Ge(3) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Tb(1), one Cu(1), and one Ge(2) atom. In the eleventh O site, O(11) is bonded in a distorted see-saw-like geometry to one Mg(1), one Tb(2), one Cu(1), and one Ge(1) atom. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Ge(2) and one Ge(4) atom. is represented by the CIF card [CIF]
data_Tb2MgCu(GeO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.368
_cell_length_b   7.310
_cell_length_c   7.652
_cell_angle_alpha   68.325
_cell_angle_beta   88.818
_cell_angle_gamma   79.498
_symmetry_Int_Tables_number   1
_cell_volume   273.998
_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
  Tb  Tb0  1  0.049  0.766  0.424  1.0
  Tb  Tb1  1  0.974  0.221  0.558  1.0
  Mg  Mg2  1  0.092  0.727  0.920  1.0
  Cu  Cu3  1  0.962  0.068  0.004  1.0
  Ge  Ge4  1  0.549  0.873  0.765  1.0
  Ge  Ge5  1  0.472  0.156  0.226  1.0
  Ge  Ge6  1  0.591  0.579  0.219  1.0
  Ge  Ge7  1  0.426  0.406  0.779  1.0
  O  O8  1  0.862  0.875  0.647  1.0
  O  O9  1  0.241  0.060  0.381  1.0
  O  O10  1  0.776  0.570  0.407  1.0
  O  O11  1  0.213  0.429  0.598  1.0
  O  O12  1  0.375  0.674  0.735  1.0
  O  O13  1  0.639  0.305  0.308  1.0
  O  O14  1  0.736  0.678  0.997  1.0
  O  O15  1  0.720  0.263  0.781  1.0
  O  O16  1  0.265  0.675  0.185  1.0
  O  O17  1  0.732  0.981  0.205  1.0
  O  O18  1  0.201  0.003  0.834  1.0
  O  O19  1  0.299  0.330  0.011  1.0
[/CIF]
.