The compound described by MgTh9YO20 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 7-coordinate geometry to one O(11), one O(13), one O(15), one O(17), one O(20), one O(3), and one O(5) atom. There are nine inequivalent Th sites. In the first Th site, Th(1) is bonded in a body-centered cubic geometry to one O(1), one O(10), one O(13), one O(17), one O(20), one O(3), one O(5), and one O(7) atom. In the second Th site, Th(2) is bonded in a body-centered cubic geometry to one O(10), one O(14), one O(15), one O(16), one O(4), one O(6), one O(7), and one O(9) atom. In the third Th site, Th(3) is bonded in a body-centered cubic geometry to one O(1), one O(12), one O(17), one O(19), one O(2), one O(6), one O(8), and one O(9) atom. In the fourth Th site, Th(4) is bonded in a body-centered cubic geometry to one O(1), one O(11), one O(12), one O(13), one O(16), one O(18), one O(3), and one O(7) atom. In the fifth Th site, Th(5) is bonded in a distorted body-centered cubic geometry to one O(10), one O(11), one O(13), one O(14), one O(19), one O(2), one O(20), and one O(5) atom. In the sixth Th site, Th(6) is bonded in a body-centered cubic geometry to one O(12), one O(14), one O(15), one O(17), one O(2), one O(3), one O(4), and one O(6) atom. In the seventh Th site, Th(7) is bonded in a distorted body-centered cubic geometry to one O(1), one O(15), one O(17), one O(18), one O(20), one O(5), one O(8), and one O(9) atom. In the eighth Th site, Th(8) is bonded in a body-centered cubic geometry to one O(11), one O(14), one O(16), one O(18), one O(19), one O(5), one O(6), and one O(7) atom. In the ninth Th site, Th(9) is bonded in a body-centered cubic geometry to one O(11), one O(12), one O(15), one O(18), one O(20), one O(3), one O(4), and one O(8) atom. Y(1) is bonded in a body-centered cubic geometry to one O(10), one O(13), one O(16), one O(19), one O(2), one O(4), one O(8), and one O(9) atom. There are twenty inequivalent O sites. In the first O site, O(1) is bonded to one Th(1), one Th(3), one Th(4), and one Th(7) atom to form OTh4 tetrahedra that share  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(16)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(2)YTh3 tetrahedra, corners with two equivalent O(8)YTh3 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid, corners with two equivalent O(13)YTh3Mg trigonal bipyramids,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(9)YTh3 tetrahedra, and  an edgeedge with one O(17)Th4Mg trigonal bipyramid. In the second O site, O(2) is bonded to one Th(3), one Th(5), one Th(6), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(16)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra, corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(10)YTh3 tetrahedra, corners with two equivalent O(8)YTh3 tetrahedra, corners with two equivalent O(17)Th4Mg trigonal bipyramids,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra,  an edgeedge with one O(4)YTh3 tetrahedra,  an edgeedge with one O(9)YTh3 tetrahedra, and  an edgeedge with one O(13)YTh3Mg trigonal bipyramid. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Mg(1), one Th(1), one Th(4), one Th(6), and one Th(9) atom. In the fourth O site, O(4) is bonded to one Th(2), one Th(6), one Th(9), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(16)YTh3 tetrahedra, corners with two equivalent O(9)YTh3 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra,  an edgeedge with one O(2)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Mg(1), one Th(1), one Th(5), one Th(7), and one Th(8) atom. In the sixth O site, O(6) is bonded to one Th(2), one Th(3), one Th(6), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(16)YTh3 tetrahedra, corners with two equivalent O(2)YTh3 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra,  an edgeedge with one O(4)YTh3 tetrahedra,  an edgeedge with one O(9)YTh3 tetrahedra, and  an edgeedge with one O(17)Th4Mg trigonal bipyramid. In the seventh O site, O(7) is bonded to one Th(1), one Th(2), one Th(4), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(16)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid, corners with two equivalent O(13)YTh3Mg trigonal bipyramids,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra, and  an edgeedge with one O(16)YTh3 tetrahedra. In the eighth O site, O(8) is bonded to one Th(3), one Th(7), one Th(9), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(16)YTh3 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(1)Th4 tetrahedra, corners with two equivalent O(2)YTh3 tetrahedra,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra,  an edgeedge with one O(4)YTh3 tetrahedra,  an edgeedge with one O(9)YTh3 tetrahedra, and  an edgeedge with one O(17)Th4Mg trigonal bipyramid. In the ninth O site, O(9) is bonded to one Th(2), one Th(3), one Th(7), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(10)YTh3 tetrahedra, corners with two equivalent O(19)YTh3 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid, corners with two equivalent O(17)Th4Mg trigonal bipyramids,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(16)YTh3 tetrahedra,  an edgeedge with one O(2)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the tenth O site, O(10) is bonded to one Th(1), one Th(2), one Th(5), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(16)YTh3 tetrahedra, corners with two equivalent O(2)YTh3 tetrahedra, corners with two equivalent O(9)YTh3 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra,  an edgeedge with one O(4)YTh3 tetrahedra, and  an edgeedge with one O(13)YTh3Mg trigonal bipyramid. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Mg(1), one Th(4), one Th(5), one Th(8), and one Th(9) atom. In the twelfth O site, O(12) is bonded to one Th(3), one Th(4), one Th(6), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(16)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra, corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid, corners with two equivalent O(17)Th4Mg trigonal bipyramids,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(2)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the thirteenth O site, O(13) is bonded to one Mg(1), one Th(1), one Th(4), one Th(5), and one Y(1) atom to form distorted OYTh3Mg trigonal bipyramids that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(1)Th4 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra, corners with two equivalent O(19)YTh3 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra,  an edgeedge with one O(16)YTh3 tetrahedra,  an edgeedge with one O(2)YTh3 tetrahedra, and  an edgeedge with one O(17)Th4Mg trigonal bipyramid. In the fourteenth O site, O(14) is bonded to one Th(2), one Th(5), one Th(6), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra, corners with two equivalent O(19)YTh3 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra,  an edgeedge with one O(16)YTh3 tetrahedra, and  an edgeedge with one O(2)YTh3 tetrahedra. In the fifteenth O site, O(15) is bonded in a 5-coordinate geometry to one Mg(1), one Th(2), one Th(6), one Th(7), and one Th(9) atom. In the sixteenth O site, O(16) is bonded to one Th(2), one Th(4), one Th(8), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(2)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(10)YTh3 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra,  an edgeedge with one O(9)YTh3 tetrahedra, and  an edgeedge with one O(13)YTh3Mg trigonal bipyramid. In the seventeenth O site, O(17) is bonded to one Mg(1), one Th(1), one Th(3), one Th(6), and one Th(7) atom to form distorted OTh4Mg trigonal bipyramids that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(2)YTh3 tetrahedra, corners with two equivalent O(9)YTh3 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(8)YTh3 tetrahedra, and  an edgeedge with one O(13)YTh3Mg trigonal bipyramid. In the eighteenth O site, O(18) is bonded to one Th(4), one Th(7), one Th(8), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(16)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the nineteenth O site, O(19) is bonded to one Th(3), one Th(5), one Th(8), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(2)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(9)YTh3 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid, corners with two equivalent O(13)YTh3Mg trigonal bipyramids,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra,  an edgeedge with one O(16)YTh3 tetrahedra,  an edgeedge with one O(2)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the twentieth O site, O(20) is bonded in a 5-coordinate geometry to one Mg(1), one Th(1), one Th(5), one Th(7), and one Th(9) atom. is represented by the CIF file [CIF]
data_YTh9MgO20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.996
_cell_length_b   19.978
_cell_length_c   10.559
_cell_angle_alpha   19.076
_cell_angle_beta   55.610
_cell_angle_gamma   60.159
_symmetry_Int_Tables_number   1
_cell_volume   450.778
_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
  Y  Y0  1  0.996  0.005  0.994  1.0
  Th  Th1  1  0.010  0.173  0.047  1.0
  Th  Th2  1  0.504  0.002  0.994  1.0
  Th  Th3  1  0.993  0.404  0.994  1.0
  Th  Th4  1  0.501  0.197  0.003  1.0
  Th  Th5  1  0.014  0.602  0.968  1.0
  Th  Th6  1  0.494  0.393  0.015  1.0
  Th  Th7  1  0.010  0.819  0.978  1.0
  Th  Th8  1  0.495  0.602  0.999  1.0
  Th  Th9  1  0.489  0.802  0.004  1.0
  Mg  Mg10  1  0.802  0.514  0.448  1.0
  O  O11  1  0.121  0.145  0.259  1.0
  O  O12  1  0.122  0.348  0.253  1.0
  O  O13  1  0.628  0.136  0.277  1.0
  O  O14  1  0.375  0.052  0.748  1.0
  O  O15  1  0.119  0.543  0.266  1.0
  O  O16  1  0.620  0.353  0.246  1.0
  O  O17  1  0.373  0.245  0.760  1.0
  O  O18  1  0.121  0.759  0.239  1.0
  O  O19  1  0.873  0.058  0.739  1.0
  O  O20  1  0.124  0.950  0.248  1.0
  O  O21  1  0.626  0.550  0.246  1.0
  O  O22  1  0.350  0.446  0.766  1.0
  O  O23  1  0.872  0.265  0.733  1.0
  O  O24  1  0.374  0.650  0.747  1.0
  O  O25  1  0.627  0.756  0.241  1.0
  O  O26  1  0.622  0.951  0.254  1.0
  O  O27  1  0.874  0.452  0.740  1.0
  O  O28  1  0.370  0.850  0.754  1.0
  O  O29  1  0.873  0.650  0.746  1.0
  O  O30  1  0.878  0.827  0.793  1.0
[/CIF]
.
The compound described by MgTh9YO20 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 7-coordinate geometry to one O(11), one O(13), one O(15), one O(17), one O(20), one O(3), and one O(5) atom. There are nine inequivalent Th sites. In the first Th site, Th(1) is bonded in a body-centered cubic geometry to one O(1), one O(10), one O(13), one O(17), one O(20), one O(3), one O(5), and one O(7) atom. In the second Th site, Th(2) is bonded in a body-centered cubic geometry to one O(10), one O(14), one O(15), one O(16), one O(4), one O(6), one O(7), and one O(9) atom. In the third Th site, Th(3) is bonded in a body-centered cubic geometry to one O(1), one O(12), one O(17), one O(19), one O(2), one O(6), one O(8), and one O(9) atom. In the fourth Th site, Th(4) is bonded in a body-centered cubic geometry to one O(1), one O(11), one O(12), one O(13), one O(16), one O(18), one O(3), and one O(7) atom. In the fifth Th site, Th(5) is bonded in a distorted body-centered cubic geometry to one O(10), one O(11), one O(13), one O(14), one O(19), one O(2), one O(20), and one O(5) atom. In the sixth Th site, Th(6) is bonded in a body-centered cubic geometry to one O(12), one O(14), one O(15), one O(17), one O(2), one O(3), one O(4), and one O(6) atom. In the seventh Th site, Th(7) is bonded in a distorted body-centered cubic geometry to one O(1), one O(15), one O(17), one O(18), one O(20), one O(5), one O(8), and one O(9) atom. In the eighth Th site, Th(8) is bonded in a body-centered cubic geometry to one O(11), one O(14), one O(16), one O(18), one O(19), one O(5), one O(6), and one O(7) atom. In the ninth Th site, Th(9) is bonded in a body-centered cubic geometry to one O(11), one O(12), one O(15), one O(18), one O(20), one O(3), one O(4), and one O(8) atom. Y(1) is bonded in a body-centered cubic geometry to one O(10), one O(13), one O(16), one O(19), one O(2), one O(4), one O(8), and one O(9) atom. There are twenty inequivalent O sites. In the first O site, O(1) is bonded to one Th(1), one Th(3), one Th(4), and one Th(7) atom to form OTh4 tetrahedra that share  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(16)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(2)YTh3 tetrahedra, corners with two equivalent O(8)YTh3 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid, corners with two equivalent O(13)YTh3Mg trigonal bipyramids,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(9)YTh3 tetrahedra, and  an edgeedge with one O(17)Th4Mg trigonal bipyramid. In the second O site, O(2) is bonded to one Th(3), one Th(5), one Th(6), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(16)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra, corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(10)YTh3 tetrahedra, corners with two equivalent O(8)YTh3 tetrahedra, corners with two equivalent O(17)Th4Mg trigonal bipyramids,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra,  an edgeedge with one O(4)YTh3 tetrahedra,  an edgeedge with one O(9)YTh3 tetrahedra, and  an edgeedge with one O(13)YTh3Mg trigonal bipyramid. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Mg(1), one Th(1), one Th(4), one Th(6), and one Th(9) atom. In the fourth O site, O(4) is bonded to one Th(2), one Th(6), one Th(9), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(16)YTh3 tetrahedra, corners with two equivalent O(9)YTh3 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra,  an edgeedge with one O(2)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Mg(1), one Th(1), one Th(5), one Th(7), and one Th(8) atom. In the sixth O site, O(6) is bonded to one Th(2), one Th(3), one Th(6), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(16)YTh3 tetrahedra, corners with two equivalent O(2)YTh3 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra,  an edgeedge with one O(4)YTh3 tetrahedra,  an edgeedge with one O(9)YTh3 tetrahedra, and  an edgeedge with one O(17)Th4Mg trigonal bipyramid. In the seventh O site, O(7) is bonded to one Th(1), one Th(2), one Th(4), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(16)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid, corners with two equivalent O(13)YTh3Mg trigonal bipyramids,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra, and  an edgeedge with one O(16)YTh3 tetrahedra. In the eighth O site, O(8) is bonded to one Th(3), one Th(7), one Th(9), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(16)YTh3 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(1)Th4 tetrahedra, corners with two equivalent O(2)YTh3 tetrahedra,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid,  an edgeedge with one O(12)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra,  an edgeedge with one O(4)YTh3 tetrahedra,  an edgeedge with one O(9)YTh3 tetrahedra, and  an edgeedge with one O(17)Th4Mg trigonal bipyramid. In the ninth O site, O(9) is bonded to one Th(2), one Th(3), one Th(7), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(10)YTh3 tetrahedra, corners with two equivalent O(19)YTh3 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid, corners with two equivalent O(17)Th4Mg trigonal bipyramids,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(16)YTh3 tetrahedra,  an edgeedge with one O(2)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the tenth O site, O(10) is bonded to one Th(1), one Th(2), one Th(5), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(16)YTh3 tetrahedra, corners with two equivalent O(2)YTh3 tetrahedra, corners with two equivalent O(9)YTh3 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra,  an edgeedge with one O(4)YTh3 tetrahedra, and  an edgeedge with one O(13)YTh3Mg trigonal bipyramid. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Mg(1), one Th(4), one Th(5), one Th(8), and one Th(9) atom. In the twelfth O site, O(12) is bonded to one Th(3), one Th(4), one Th(6), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(16)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(18)Th4 tetrahedra, corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid, corners with two equivalent O(17)Th4Mg trigonal bipyramids,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(2)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the thirteenth O site, O(13) is bonded to one Mg(1), one Th(1), one Th(4), one Th(5), and one Y(1) atom to form distorted OYTh3Mg trigonal bipyramids that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(1)Th4 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra, corners with two equivalent O(19)YTh3 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra,  an edgeedge with one O(16)YTh3 tetrahedra,  an edgeedge with one O(2)YTh3 tetrahedra, and  an edgeedge with one O(17)Th4Mg trigonal bipyramid. In the fourteenth O site, O(14) is bonded to one Th(2), one Th(5), one Th(6), and one Th(8) atom to form OTh4 tetrahedra that share  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra, corners with two equivalent O(19)YTh3 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra,  an edgeedge with one O(16)YTh3 tetrahedra, and  an edgeedge with one O(2)YTh3 tetrahedra. In the fifteenth O site, O(15) is bonded in a 5-coordinate geometry to one Mg(1), one Th(2), one Th(6), one Th(7), and one Th(9) atom. In the sixteenth O site, O(16) is bonded to one Th(2), one Th(4), one Th(8), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(2)YTh3 tetrahedra,  a cornercorner with one O(8)YTh3 tetrahedra, corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(10)YTh3 tetrahedra, corners with two equivalent O(4)YTh3 tetrahedra,  an edgeedge with one O(14)Th4 tetrahedra,  an edgeedge with one O(18)Th4 tetrahedra,  an edgeedge with one O(7)Th4 tetrahedra,  an edgeedge with one O(19)YTh3 tetrahedra,  an edgeedge with one O(9)YTh3 tetrahedra, and  an edgeedge with one O(13)YTh3Mg trigonal bipyramid. In the seventeenth O site, O(17) is bonded to one Mg(1), one Th(1), one Th(3), one Th(6), and one Th(7) atom to form distorted OTh4Mg trigonal bipyramids that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(10)YTh3 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(2)YTh3 tetrahedra, corners with two equivalent O(9)YTh3 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(8)YTh3 tetrahedra, and  an edgeedge with one O(13)YTh3Mg trigonal bipyramid. In the eighteenth O site, O(18) is bonded to one Th(4), one Th(7), one Th(8), and one Th(9) atom to form OTh4 tetrahedra that share  a cornercorner with one O(14)Th4 tetrahedra,  a cornercorner with one O(6)Th4 tetrahedra,  a cornercorner with one O(19)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra,  a cornercorner with one O(9)YTh3 tetrahedra, corners with two equivalent O(12)Th4 tetrahedra, corners with two equivalent O(7)Th4 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid,  a cornercorner with one O(13)YTh3Mg trigonal bipyramid,  an edgeedge with one O(1)Th4 tetrahedra,  an edgeedge with one O(16)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the nineteenth O site, O(19) is bonded to one Th(3), one Th(5), one Th(8), and one Y(1) atom to form OYTh3 tetrahedra that share  a cornercorner with one O(1)Th4 tetrahedra,  a cornercorner with one O(12)Th4 tetrahedra,  a cornercorner with one O(18)Th4 tetrahedra,  a cornercorner with one O(7)Th4 tetrahedra,  a cornercorner with one O(2)YTh3 tetrahedra,  a cornercorner with one O(4)YTh3 tetrahedra, corners with two equivalent O(14)Th4 tetrahedra, corners with two equivalent O(9)YTh3 tetrahedra,  a cornercorner with one O(17)Th4Mg trigonal bipyramid, corners with two equivalent O(13)YTh3Mg trigonal bipyramids,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(10)YTh3 tetrahedra,  an edgeedge with one O(16)YTh3 tetrahedra,  an edgeedge with one O(2)YTh3 tetrahedra, and  an edgeedge with one O(8)YTh3 tetrahedra. In the twentieth O site, O(20) is bonded in a 5-coordinate geometry to one Mg(1), one Th(1), one Th(5), one Th(7), and one Th(9) atom. is represented by the CIF file [CIF]
data_YTh9MgO20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.996
_cell_length_b   19.978
_cell_length_c   10.559
_cell_angle_alpha   19.076
_cell_angle_beta   55.610
_cell_angle_gamma   60.159
_symmetry_Int_Tables_number   1
_cell_volume   450.778
_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
  Y  Y0  1  0.996  0.005  0.994  1.0
  Th  Th1  1  0.010  0.173  0.047  1.0
  Th  Th2  1  0.504  0.002  0.994  1.0
  Th  Th3  1  0.993  0.404  0.994  1.0
  Th  Th4  1  0.501  0.197  0.003  1.0
  Th  Th5  1  0.014  0.602  0.968  1.0
  Th  Th6  1  0.494  0.393  0.015  1.0
  Th  Th7  1  0.010  0.819  0.978  1.0
  Th  Th8  1  0.495  0.602  0.999  1.0
  Th  Th9  1  0.489  0.802  0.004  1.0
  Mg  Mg10  1  0.802  0.514  0.448  1.0
  O  O11  1  0.121  0.145  0.259  1.0
  O  O12  1  0.122  0.348  0.253  1.0
  O  O13  1  0.628  0.136  0.277  1.0
  O  O14  1  0.375  0.052  0.748  1.0
  O  O15  1  0.119  0.543  0.266  1.0
  O  O16  1  0.620  0.353  0.246  1.0
  O  O17  1  0.373  0.245  0.760  1.0
  O  O18  1  0.121  0.759  0.239  1.0
  O  O19  1  0.873  0.058  0.739  1.0
  O  O20  1  0.124  0.950  0.248  1.0
  O  O21  1  0.626  0.550  0.246  1.0
  O  O22  1  0.350  0.446  0.766  1.0
  O  O23  1  0.872  0.265  0.733  1.0
  O  O24  1  0.374  0.650  0.747  1.0
  O  O25  1  0.627  0.756  0.241  1.0
  O  O26  1  0.622  0.951  0.254  1.0
  O  O27  1  0.874  0.452  0.740  1.0
  O  O28  1  0.370  0.850  0.754  1.0
  O  O29  1  0.873  0.650  0.746  1.0
  O  O30  1  0.878  0.827  0.793  1.0
[/CIF]
.