The structure described by MgEr5(MoO6)2 crystallizes in the triclinic P1 space group. Mg(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(7), and one O(8) atom. There are five inequivalent Er sites. In the first Er site, Er(1) is bonded to one O(12), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form distorted ErO7 pentagonal bipyramids that share corners with two equivalent Er(5)O6 octahedra,  an edgeedge with one Er(5)O6 octahedra,  an edgeedge with one Mo(1)O6 octahedra,  an edgeedge with one Mo(2)O6 octahedra, and edges with two equivalent Er(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 54°. In the second Er site, Er(2) is bonded to one O(1), one O(11), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form distorted ErO7 pentagonal bipyramids that share corners with two equivalent Er(5)O6 octahedra,  an edgeedge with one Er(5)O6 octahedra,  an edgeedge with one Mo(1)O6 octahedra,  an edgeedge with one Mo(2)O6 octahedra, and edges with two equivalent Er(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 61°. In the third Er site, Er(3) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. In the fourth Er site, Er(4) is bonded in a 7-coordinate geometry to one O(1), one O(12), one O(2), one O(3), one O(4), one O(7), and one O(8) atom. In the fifth Er site, Er(5) is bonded to one O(10), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form ErO6 octahedra that share corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Mo(2)O6 octahedra, corners with two equivalent Er(1)O7 pentagonal bipyramids, corners with two equivalent Er(2)O7 pentagonal bipyramids,  an edgeedge with one Er(1)O7 pentagonal bipyramid, and  an edgeedge with one Er(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 42-43°. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(1), one O(10), one O(11), one O(12), one O(4), and one O(9) atom to form MoO6 octahedra that share corners with two equivalent Er(5)O6 octahedra, edges with two equivalent Mo(2)O6 octahedra,  an edgeedge with one Er(1)O7 pentagonal bipyramid, and  an edgeedge with one Er(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 42-43°. In the second Mo site, Mo(2) is bonded to one O(10), one O(11), one O(12), one O(2), one O(3), and one O(9) atom to form MoO6 octahedra that share corners with two equivalent Er(5)O6 octahedra, edges with two equivalent Mo(1)O6 octahedra,  an edgeedge with one Er(1)O7 pentagonal bipyramid, and  an edgeedge with one Er(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 42-43°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Er(2), one Er(3), one Er(4), and one Mo(1) atom to form distorted OEr3MgMo trigonal bipyramids that share corners with two equivalent O(6)Er4 tetrahedra,  a cornercorner with one O(7)Er4Mg trigonal bipyramid, corners with three equivalent O(8)Er4Mg trigonal bipyramids,  a cornercorner with one O(11)Er2Mo2 trigonal pyramid,  an edgeedge with one O(5)Er4 tetrahedra,  an edgeedge with one O(7)Er4Mg trigonal bipyramid, edges with two equivalent O(2)Er3MgMo trigonal bipyramids,  an edgeedge with one O(11)Er2Mo2 trigonal pyramid, and  an edgeedge with one O(12)Er2Mo2 trigonal pyramid. In the second O site, O(2) is bonded to one Mg(1), one Er(2), one Er(3), one Er(4), and one Mo(2) atom to form distorted OEr3MgMo trigonal bipyramids that share corners with two equivalent O(5)Er4 tetrahedra,  a cornercorner with one O(8)Er4Mg trigonal bipyramid, corners with three equivalent O(7)Er4Mg trigonal bipyramids,  a cornercorner with one O(11)Er2Mo2 trigonal pyramid,  an edgeedge with one O(6)Er4 tetrahedra,  an edgeedge with one O(8)Er4Mg trigonal bipyramid, edges with two equivalent O(1)Er3MgMo trigonal bipyramids,  an edgeedge with one O(11)Er2Mo2 trigonal pyramid, and  an edgeedge with one O(12)Er2Mo2 trigonal pyramid. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Mg(1), one Er(1), one Er(3), one Er(4), and one Mo(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(1), one Er(1), one Er(3), one Er(4), and one Mo(1) atom. In the fifth O site, O(5) is bonded to one Er(1), one Er(2), one Er(3), and one Er(5) atom to form OEr4 tetrahedra that share  a cornercorner with one O(7)Er4Mg trigonal bipyramid, corners with two equivalent O(2)Er3MgMo trigonal bipyramids, corners with three equivalent O(8)Er4Mg trigonal bipyramids,  a cornercorner with one O(12)Er2Mo2 trigonal pyramid, corners with two equivalent O(11)Er2Mo2 trigonal pyramids, edges with two equivalent O(6)Er4 tetrahedra,  an edgeedge with one O(1)Er3MgMo trigonal bipyramid, and  an edgeedge with one O(7)Er4Mg trigonal bipyramid. In the sixth O site, O(6) is bonded to one Er(1), one Er(2), one Er(3), and one Er(5) atom to form OEr4 tetrahedra that share  a cornercorner with one O(8)Er4Mg trigonal bipyramid, corners with two equivalent O(1)Er3MgMo trigonal bipyramids, corners with three equivalent O(7)Er4Mg trigonal bipyramids,  a cornercorner with one O(12)Er2Mo2 trigonal pyramid, corners with two equivalent O(11)Er2Mo2 trigonal pyramids, edges with two equivalent O(5)Er4 tetrahedra,  an edgeedge with one O(2)Er3MgMo trigonal bipyramid, and  an edgeedge with one O(8)Er4Mg trigonal bipyramid. In the seventh O site, O(7) is bonded to one Mg(1), one Er(1), one Er(2), one Er(4), and one Er(5) atom to form distorted OEr4Mg trigonal bipyramids that share  a cornercorner with one O(5)Er4 tetrahedra, corners with three equivalent O(6)Er4 tetrahedra,  a cornercorner with one O(1)Er3MgMo trigonal bipyramid, corners with three equivalent O(2)Er3MgMo trigonal bipyramids,  a cornercorner with one O(11)Er2Mo2 trigonal pyramid, corners with two equivalent O(12)Er2Mo2 trigonal pyramids,  an edgeedge with one O(5)Er4 tetrahedra,  an edgeedge with one O(1)Er3MgMo trigonal bipyramid,  an edgeedge with one O(8)Er4Mg trigonal bipyramid, and  a faceface with one O(8)Er4Mg trigonal bipyramid. In the eighth O site, O(8) is bonded to one Mg(1), one Er(1), one Er(2), one Er(4), and one Er(5) atom to form distorted OEr4Mg trigonal bipyramids that share  a cornercorner with one O(6)Er4 tetrahedra, corners with three equivalent O(5)Er4 tetrahedra,  a cornercorner with one O(2)Er3MgMo trigonal bipyramid, corners with three equivalent O(1)Er3MgMo trigonal bipyramids,  a cornercorner with one O(11)Er2Mo2 trigonal pyramid, corners with two equivalent O(12)Er2Mo2 trigonal pyramids,  an edgeedge with one O(6)Er4 tetrahedra,  an edgeedge with one O(2)Er3MgMo trigonal bipyramid,  an edgeedge with one O(7)Er4Mg trigonal bipyramid, and  a faceface with one O(7)Er4Mg trigonal bipyramid. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Er(5), one Mo(1), and one Mo(2) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Er(5), one Mo(1), and one Mo(2) atom. In the eleventh O site, O(11) is bonded to one Er(2), one Er(3), one Mo(1), and one Mo(2) atom to form OEr2Mo2 trigonal pyramids that share corners with two equivalent O(5)Er4 tetrahedra, corners with two equivalent O(6)Er4 tetrahedra,  a cornercorner with one O(1)Er3MgMo trigonal bipyramid,  a cornercorner with one O(2)Er3MgMo trigonal bipyramid,  a cornercorner with one O(7)Er4Mg trigonal bipyramid,  a cornercorner with one O(8)Er4Mg trigonal bipyramid,  an edgeedge with one O(1)Er3MgMo trigonal bipyramid,  an edgeedge with one O(2)Er3MgMo trigonal bipyramid, and  an edgeedge with one O(12)Er2Mo2 trigonal pyramid. In the twelfth O site, O(12) is bonded to one Er(1), one Er(4), one Mo(1), and one Mo(2) atom to form OEr2Mo2 trigonal pyramids that share  a cornercorner with one O(5)Er4 tetrahedra,  a cornercorner with one O(6)Er4 tetrahedra, corners with two equivalent O(7)Er4Mg trigonal bipyramids, corners with two equivalent O(8)Er4Mg trigonal bipyramids,  an edgeedge with one O(1)Er3MgMo trigonal bipyramid,  an edgeedge with one O(2)Er3MgMo trigonal bipyramid, and  an edgeedge with one O(11)Er2Mo2 trigonal pyramid. is represented by the CIF file [CIF]
data_Er5Mg(MoO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.888
_cell_length_b   6.920
_cell_length_c   7.472
_cell_angle_alpha   105.447
_cell_angle_beta   90.002
_cell_angle_gamma   115.151
_symmetry_Int_Tables_number   1
_cell_volume   263.378
_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
  Er  Er0  1  0.314  0.629  0.635  1.0
  Er  Er1  1  0.696  0.391  0.358  1.0
  Er  Er2  1  0.324  0.648  0.200  1.0
  Er  Er3  1  0.696  0.392  0.838  1.0
  Er  Er4  1  0.995  0.991  0.484  1.0
  Mg  Mg5  1  0.172  0.343  0.855  1.0
  Mo  Mo6  1  0.758  0.993  0.998  1.0
  Mo  Mo7  1  0.235  0.993  0.998  1.0
  O  O8  1  0.929  0.347  0.079  1.0
  O  O9  1  0.418  0.347  0.079  1.0
  O  O10  1  0.100  0.642  0.901  1.0
  O  O11  1  0.544  0.643  0.901  1.0
  O  O12  1  0.092  0.690  0.429  1.0
  O  O13  1  0.598  0.689  0.429  1.0
  O  O14  1  0.914  0.306  0.585  1.0
  O  O15  1  0.392  0.306  0.586  1.0
  O  O16  1  0.988  0.977  0.196  1.0
  O  O17  1  0.005  0.011  0.793  1.0
  O  O18  1  0.505  0.008  0.196  1.0
  O  O19  1  0.503  0.006  0.809  1.0
[/CIF]
.
The structure described by MgEr5(MoO6)2 crystallizes in the triclinic P1 space group. Mg(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(7), and one O(8) atom. There are five inequivalent Er sites. In the first Er site, Er(1) is bonded to one O(12), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form distorted ErO7 pentagonal bipyramids that share corners with two equivalent Er(5)O6 octahedra,  an edgeedge with one Er(5)O6 octahedra,  an edgeedge with one Mo(1)O6 octahedra,  an edgeedge with one Mo(2)O6 octahedra, and edges with two equivalent Er(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 54°. In the second Er site, Er(2) is bonded to one O(1), one O(11), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form distorted ErO7 pentagonal bipyramids that share corners with two equivalent Er(5)O6 octahedra,  an edgeedge with one Er(5)O6 octahedra,  an edgeedge with one Mo(1)O6 octahedra,  an edgeedge with one Mo(2)O6 octahedra, and edges with two equivalent Er(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 61°. In the third Er site, Er(3) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. In the fourth Er site, Er(4) is bonded in a 7-coordinate geometry to one O(1), one O(12), one O(2), one O(3), one O(4), one O(7), and one O(8) atom. In the fifth Er site, Er(5) is bonded to one O(10), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form ErO6 octahedra that share corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Mo(2)O6 octahedra, corners with two equivalent Er(1)O7 pentagonal bipyramids, corners with two equivalent Er(2)O7 pentagonal bipyramids,  an edgeedge with one Er(1)O7 pentagonal bipyramid, and  an edgeedge with one Er(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 42-43°. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(1), one O(10), one O(11), one O(12), one O(4), and one O(9) atom to form MoO6 octahedra that share corners with two equivalent Er(5)O6 octahedra, edges with two equivalent Mo(2)O6 octahedra,  an edgeedge with one Er(1)O7 pentagonal bipyramid, and  an edgeedge with one Er(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 42-43°. In the second Mo site, Mo(2) is bonded to one O(10), one O(11), one O(12), one O(2), one O(3), and one O(9) atom to form MoO6 octahedra that share corners with two equivalent Er(5)O6 octahedra, edges with two equivalent Mo(1)O6 octahedra,  an edgeedge with one Er(1)O7 pentagonal bipyramid, and  an edgeedge with one Er(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 42-43°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Er(2), one Er(3), one Er(4), and one Mo(1) atom to form distorted OEr3MgMo trigonal bipyramids that share corners with two equivalent O(6)Er4 tetrahedra,  a cornercorner with one O(7)Er4Mg trigonal bipyramid, corners with three equivalent O(8)Er4Mg trigonal bipyramids,  a cornercorner with one O(11)Er2Mo2 trigonal pyramid,  an edgeedge with one O(5)Er4 tetrahedra,  an edgeedge with one O(7)Er4Mg trigonal bipyramid, edges with two equivalent O(2)Er3MgMo trigonal bipyramids,  an edgeedge with one O(11)Er2Mo2 trigonal pyramid, and  an edgeedge with one O(12)Er2Mo2 trigonal pyramid. In the second O site, O(2) is bonded to one Mg(1), one Er(2), one Er(3), one Er(4), and one Mo(2) atom to form distorted OEr3MgMo trigonal bipyramids that share corners with two equivalent O(5)Er4 tetrahedra,  a cornercorner with one O(8)Er4Mg trigonal bipyramid, corners with three equivalent O(7)Er4Mg trigonal bipyramids,  a cornercorner with one O(11)Er2Mo2 trigonal pyramid,  an edgeedge with one O(6)Er4 tetrahedra,  an edgeedge with one O(8)Er4Mg trigonal bipyramid, edges with two equivalent O(1)Er3MgMo trigonal bipyramids,  an edgeedge with one O(11)Er2Mo2 trigonal pyramid, and  an edgeedge with one O(12)Er2Mo2 trigonal pyramid. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Mg(1), one Er(1), one Er(3), one Er(4), and one Mo(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(1), one Er(1), one Er(3), one Er(4), and one Mo(1) atom. In the fifth O site, O(5) is bonded to one Er(1), one Er(2), one Er(3), and one Er(5) atom to form OEr4 tetrahedra that share  a cornercorner with one O(7)Er4Mg trigonal bipyramid, corners with two equivalent O(2)Er3MgMo trigonal bipyramids, corners with three equivalent O(8)Er4Mg trigonal bipyramids,  a cornercorner with one O(12)Er2Mo2 trigonal pyramid, corners with two equivalent O(11)Er2Mo2 trigonal pyramids, edges with two equivalent O(6)Er4 tetrahedra,  an edgeedge with one O(1)Er3MgMo trigonal bipyramid, and  an edgeedge with one O(7)Er4Mg trigonal bipyramid. In the sixth O site, O(6) is bonded to one Er(1), one Er(2), one Er(3), and one Er(5) atom to form OEr4 tetrahedra that share  a cornercorner with one O(8)Er4Mg trigonal bipyramid, corners with two equivalent O(1)Er3MgMo trigonal bipyramids, corners with three equivalent O(7)Er4Mg trigonal bipyramids,  a cornercorner with one O(12)Er2Mo2 trigonal pyramid, corners with two equivalent O(11)Er2Mo2 trigonal pyramids, edges with two equivalent O(5)Er4 tetrahedra,  an edgeedge with one O(2)Er3MgMo trigonal bipyramid, and  an edgeedge with one O(8)Er4Mg trigonal bipyramid. In the seventh O site, O(7) is bonded to one Mg(1), one Er(1), one Er(2), one Er(4), and one Er(5) atom to form distorted OEr4Mg trigonal bipyramids that share  a cornercorner with one O(5)Er4 tetrahedra, corners with three equivalent O(6)Er4 tetrahedra,  a cornercorner with one O(1)Er3MgMo trigonal bipyramid, corners with three equivalent O(2)Er3MgMo trigonal bipyramids,  a cornercorner with one O(11)Er2Mo2 trigonal pyramid, corners with two equivalent O(12)Er2Mo2 trigonal pyramids,  an edgeedge with one O(5)Er4 tetrahedra,  an edgeedge with one O(1)Er3MgMo trigonal bipyramid,  an edgeedge with one O(8)Er4Mg trigonal bipyramid, and  a faceface with one O(8)Er4Mg trigonal bipyramid. In the eighth O site, O(8) is bonded to one Mg(1), one Er(1), one Er(2), one Er(4), and one Er(5) atom to form distorted OEr4Mg trigonal bipyramids that share  a cornercorner with one O(6)Er4 tetrahedra, corners with three equivalent O(5)Er4 tetrahedra,  a cornercorner with one O(2)Er3MgMo trigonal bipyramid, corners with three equivalent O(1)Er3MgMo trigonal bipyramids,  a cornercorner with one O(11)Er2Mo2 trigonal pyramid, corners with two equivalent O(12)Er2Mo2 trigonal pyramids,  an edgeedge with one O(6)Er4 tetrahedra,  an edgeedge with one O(2)Er3MgMo trigonal bipyramid,  an edgeedge with one O(7)Er4Mg trigonal bipyramid, and  a faceface with one O(7)Er4Mg trigonal bipyramid. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Er(5), one Mo(1), and one Mo(2) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Er(5), one Mo(1), and one Mo(2) atom. In the eleventh O site, O(11) is bonded to one Er(2), one Er(3), one Mo(1), and one Mo(2) atom to form OEr2Mo2 trigonal pyramids that share corners with two equivalent O(5)Er4 tetrahedra, corners with two equivalent O(6)Er4 tetrahedra,  a cornercorner with one O(1)Er3MgMo trigonal bipyramid,  a cornercorner with one O(2)Er3MgMo trigonal bipyramid,  a cornercorner with one O(7)Er4Mg trigonal bipyramid,  a cornercorner with one O(8)Er4Mg trigonal bipyramid,  an edgeedge with one O(1)Er3MgMo trigonal bipyramid,  an edgeedge with one O(2)Er3MgMo trigonal bipyramid, and  an edgeedge with one O(12)Er2Mo2 trigonal pyramid. In the twelfth O site, O(12) is bonded to one Er(1), one Er(4), one Mo(1), and one Mo(2) atom to form OEr2Mo2 trigonal pyramids that share  a cornercorner with one O(5)Er4 tetrahedra,  a cornercorner with one O(6)Er4 tetrahedra, corners with two equivalent O(7)Er4Mg trigonal bipyramids, corners with two equivalent O(8)Er4Mg trigonal bipyramids,  an edgeedge with one O(1)Er3MgMo trigonal bipyramid,  an edgeedge with one O(2)Er3MgMo trigonal bipyramid, and  an edgeedge with one O(11)Er2Mo2 trigonal pyramid. is represented by the CIF file [CIF]
data_Er5Mg(MoO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.888
_cell_length_b   6.920
_cell_length_c   7.472
_cell_angle_alpha   105.447
_cell_angle_beta   90.002
_cell_angle_gamma   115.151
_symmetry_Int_Tables_number   1
_cell_volume   263.378
_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
  Er  Er0  1  0.314  0.629  0.635  1.0
  Er  Er1  1  0.696  0.391  0.358  1.0
  Er  Er2  1  0.324  0.648  0.200  1.0
  Er  Er3  1  0.696  0.392  0.838  1.0
  Er  Er4  1  0.995  0.991  0.484  1.0
  Mg  Mg5  1  0.172  0.343  0.855  1.0
  Mo  Mo6  1  0.758  0.993  0.998  1.0
  Mo  Mo7  1  0.235  0.993  0.998  1.0
  O  O8  1  0.929  0.347  0.079  1.0
  O  O9  1  0.418  0.347  0.079  1.0
  O  O10  1  0.100  0.642  0.901  1.0
  O  O11  1  0.544  0.643  0.901  1.0
  O  O12  1  0.092  0.690  0.429  1.0
  O  O13  1  0.598  0.689  0.429  1.0
  O  O14  1  0.914  0.306  0.585  1.0
  O  O15  1  0.392  0.306  0.586  1.0
  O  O16  1  0.988  0.977  0.196  1.0
  O  O17  1  0.005  0.011  0.793  1.0
  O  O18  1  0.505  0.008  0.196  1.0
  O  O19  1  0.503  0.006  0.809  1.0
[/CIF]
.