The material structure described by MgTb4(WO6)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(8) atom to form distorted MgO6 octahedra that share  a cornercorner with one W(1)O6 octahedra, edges with two equivalent W(2)O6 octahedra, and  a faceface with one W(1)O6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are four inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(3), one O(5), one O(7), and one O(9) atom. In the second Tb site, Tb(2) is bonded in a 6-coordinate geometry to one O(11), one O(12), one O(3), one O(4), one O(6), and one O(9) atom. In the third Tb site, Tb(3) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(4), one O(7), and one O(9) atom. In the fourth Tb site, Tb(4) is bonded in a 7-coordinate geometry to one O(11), one O(12), one O(3), one O(4), one O(6), one O(8), and one O(9) atom. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(10), one O(12), one O(2), one O(5), and one O(8) atom to form distorted WO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with four equivalent W(2)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-57°. In the second W site, W(2) is bonded to one O(10), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form WO6 octahedra that share corners with four equivalent W(1)O6 octahedra and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-46°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Tb(1), one Tb(3), and one W(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one W(1), and one W(2) atom. In the third O site, O(3) is bonded to one Tb(1), one Tb(2), one Tb(3), and one Tb(4) atom to form OTb4 tetrahedra that share  a cornercorner with one O(8)TbMgW2 trigonal pyramid, corners with two equivalent O(6)Tb2MgW trigonal pyramids, edges with two equivalent O(11)Tb4 tetrahedra, and edges with two equivalent O(9)Tb4 tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Tb(2), one Tb(3), and one Tb(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Tb(1), one W(1), and one W(2) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Tb(2), one Tb(4), and one W(2) atom to form distorted OTb2MgW trigonal pyramids that share corners with two equivalent O(11)Tb4 tetrahedra, corners with two equivalent O(3)Tb4 tetrahedra,  a cornercorner with one O(8)TbMgW2 trigonal pyramid,  an edgeedge with one O(9)Tb4 tetrahedra, and  an edgeedge with one O(8)TbMgW2 trigonal pyramid. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Tb(1), one Tb(3), and one W(2) atom. In the eighth O site, O(8) is bonded to one Mg(1), one Tb(4), one W(1), and one W(2) atom to form distorted OTbMgW2 trigonal pyramids that share  a cornercorner with one O(11)Tb4 tetrahedra,  a cornercorner with one O(3)Tb4 tetrahedra,  a cornercorner with one O(9)Tb4 tetrahedra,  a cornercorner with one O(6)Tb2MgW trigonal pyramid, and  an edgeedge with one O(6)Tb2MgW trigonal pyramid. In the ninth O site, O(9) is bonded to one Tb(1), one Tb(2), one Tb(3), and one Tb(4) atom to form OTb4 tetrahedra that share corners with four equivalent O(11)Tb4 tetrahedra,  a cornercorner with one O(8)TbMgW2 trigonal pyramid, edges with two equivalent O(3)Tb4 tetrahedra, and  an edgeedge with one O(6)Tb2MgW trigonal pyramid. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Mg(1), one Tb(3), one W(1), and one W(2) atom. In the eleventh O site, O(11) is bonded to one Tb(1), one Tb(2), one Tb(3), and one Tb(4) atom to form OTb4 tetrahedra that share corners with four equivalent O(9)Tb4 tetrahedra,  a cornercorner with one O(8)TbMgW2 trigonal pyramid, corners with two equivalent O(6)Tb2MgW trigonal pyramids, and edges with two equivalent O(3)Tb4 tetrahedra. In the twelfth O site, O(12) is bonded in a distorted see-saw-like geometry to one Mg(1), one Tb(2), one Tb(4), and one W(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tb4Mg(WO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.706
_cell_length_b   5.340
_cell_length_c   8.482
_cell_angle_alpha   91.632
_cell_angle_beta   92.308
_cell_angle_gamma   90.311
_symmetry_Int_Tables_number   1
_cell_volume   258.130
_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  0.208  0.513  0.333  1.0
  Tb  Tb1  1  0.224  0.052  0.610  1.0
  Tb  Tb2  1  0.731  0.964  0.365  1.0
  Tb  Tb3  1  0.755  0.467  0.630  1.0
  Mg  Mg4  1  0.625  0.962  0.823  1.0
  W  W5  1  0.055  0.983  0.001  1.0
  W  W6  1  0.534  0.473  0.009  1.0
  O  O7  1  0.052  0.857  0.215  1.0
  O  O8  1  0.336  0.788  0.922  1.0
  O  O9  1  0.975  0.254  0.455  1.0
  O  O10  1  0.548  0.817  0.592  1.0
  O  O11  1  0.253  0.310  0.080  1.0
  O  O12  1  0.473  0.302  0.802  1.0
  O  O13  1  0.550  0.647  0.207  1.0
  O  O14  1  0.792  0.668  0.916  1.0
  O  O15  1  0.480  0.278  0.459  1.0
  O  O16  1  0.734  0.200  0.070  1.0
  O  O17  1  0.005  0.737  0.515  1.0
  O  O18  1  0.946  0.131  0.789  1.0
[/CIF]
.
The material structure described by MgTb4(WO6)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(8) atom to form distorted MgO6 octahedra that share  a cornercorner with one W(1)O6 octahedra, edges with two equivalent W(2)O6 octahedra, and  a faceface with one W(1)O6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are four inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(3), one O(5), one O(7), and one O(9) atom. In the second Tb site, Tb(2) is bonded in a 6-coordinate geometry to one O(11), one O(12), one O(3), one O(4), one O(6), and one O(9) atom. In the third Tb site, Tb(3) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(4), one O(7), and one O(9) atom. In the fourth Tb site, Tb(4) is bonded in a 7-coordinate geometry to one O(11), one O(12), one O(3), one O(4), one O(6), one O(8), and one O(9) atom. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(10), one O(12), one O(2), one O(5), and one O(8) atom to form distorted WO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with four equivalent W(2)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-57°. In the second W site, W(2) is bonded to one O(10), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form WO6 octahedra that share corners with four equivalent W(1)O6 octahedra and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-46°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Tb(1), one Tb(3), and one W(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one W(1), and one W(2) atom. In the third O site, O(3) is bonded to one Tb(1), one Tb(2), one Tb(3), and one Tb(4) atom to form OTb4 tetrahedra that share  a cornercorner with one O(8)TbMgW2 trigonal pyramid, corners with two equivalent O(6)Tb2MgW trigonal pyramids, edges with two equivalent O(11)Tb4 tetrahedra, and edges with two equivalent O(9)Tb4 tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Tb(2), one Tb(3), and one Tb(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Tb(1), one W(1), and one W(2) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Tb(2), one Tb(4), and one W(2) atom to form distorted OTb2MgW trigonal pyramids that share corners with two equivalent O(11)Tb4 tetrahedra, corners with two equivalent O(3)Tb4 tetrahedra,  a cornercorner with one O(8)TbMgW2 trigonal pyramid,  an edgeedge with one O(9)Tb4 tetrahedra, and  an edgeedge with one O(8)TbMgW2 trigonal pyramid. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Tb(1), one Tb(3), and one W(2) atom. In the eighth O site, O(8) is bonded to one Mg(1), one Tb(4), one W(1), and one W(2) atom to form distorted OTbMgW2 trigonal pyramids that share  a cornercorner with one O(11)Tb4 tetrahedra,  a cornercorner with one O(3)Tb4 tetrahedra,  a cornercorner with one O(9)Tb4 tetrahedra,  a cornercorner with one O(6)Tb2MgW trigonal pyramid, and  an edgeedge with one O(6)Tb2MgW trigonal pyramid. In the ninth O site, O(9) is bonded to one Tb(1), one Tb(2), one Tb(3), and one Tb(4) atom to form OTb4 tetrahedra that share corners with four equivalent O(11)Tb4 tetrahedra,  a cornercorner with one O(8)TbMgW2 trigonal pyramid, edges with two equivalent O(3)Tb4 tetrahedra, and  an edgeedge with one O(6)Tb2MgW trigonal pyramid. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Mg(1), one Tb(3), one W(1), and one W(2) atom. In the eleventh O site, O(11) is bonded to one Tb(1), one Tb(2), one Tb(3), and one Tb(4) atom to form OTb4 tetrahedra that share corners with four equivalent O(9)Tb4 tetrahedra,  a cornercorner with one O(8)TbMgW2 trigonal pyramid, corners with two equivalent O(6)Tb2MgW trigonal pyramids, and edges with two equivalent O(3)Tb4 tetrahedra. In the twelfth O site, O(12) is bonded in a distorted see-saw-like geometry to one Mg(1), one Tb(2), one Tb(4), and one W(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tb4Mg(WO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.706
_cell_length_b   5.340
_cell_length_c   8.482
_cell_angle_alpha   91.632
_cell_angle_beta   92.308
_cell_angle_gamma   90.311
_symmetry_Int_Tables_number   1
_cell_volume   258.130
_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  0.208  0.513  0.333  1.0
  Tb  Tb1  1  0.224  0.052  0.610  1.0
  Tb  Tb2  1  0.731  0.964  0.365  1.0
  Tb  Tb3  1  0.755  0.467  0.630  1.0
  Mg  Mg4  1  0.625  0.962  0.823  1.0
  W  W5  1  0.055  0.983  0.001  1.0
  W  W6  1  0.534  0.473  0.009  1.0
  O  O7  1  0.052  0.857  0.215  1.0
  O  O8  1  0.336  0.788  0.922  1.0
  O  O9  1  0.975  0.254  0.455  1.0
  O  O10  1  0.548  0.817  0.592  1.0
  O  O11  1  0.253  0.310  0.080  1.0
  O  O12  1  0.473  0.302  0.802  1.0
  O  O13  1  0.550  0.647  0.207  1.0
  O  O14  1  0.792  0.668  0.916  1.0
  O  O15  1  0.480  0.278  0.459  1.0
  O  O16  1  0.734  0.200  0.070  1.0
  O  O17  1  0.005  0.737  0.515  1.0
  O  O18  1  0.946  0.131  0.789  1.0
[/CIF]
.