The material structure described by MgU7Zr3O20 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(13), one O(20), one O(6), and two equivalent O(1) atoms to form distorted MgO5 square pyramids that share  a cornercorner with one Zr(1)O6 pentagonal pyramid, corners with two equivalent Mg(1)O5 square pyramids,  an edgeedge with one Zr(1)O6 pentagonal pyramid, and  an edgeedge with one Zr(3)O6 pentagonal pyramid. There are seven inequivalent U sites. In the first U site, U(1) is bonded in a 7-coordinate geometry to one O(6), one O(7), one O(9), two equivalent O(13), and two equivalent O(5) atoms. In the second U site, U(2) is bonded in a body-centered cubic geometry to one O(12), one O(3), one O(7), one O(9), two equivalent O(11), and two equivalent O(4) atoms. In the third U site, U(3) is bonded in a body-centered cubic geometry to one O(10), one O(12), one O(14), one O(3), two equivalent O(17), and two equivalent O(8) atoms. In the fourth U site, U(4) is bonded in a 7-coordinate geometry to one O(11), one O(17), one O(4), two equivalent O(3), and two equivalent O(9) atoms. In the fifth U site, U(5) is bonded in a body-centered cubic geometry to one O(16), one O(18), one O(19), one O(8), two equivalent O(10), and two equivalent O(15) atoms. In the sixth U site, U(6) is bonded in a 7-coordinate geometry to one O(10), one O(14), one O(15), two equivalent O(16), and two equivalent O(19) atoms. In the seventh U site, U(7) is bonded in a 7-coordinate geometry to one O(1), one O(18), one O(19), two equivalent O(2), and two equivalent O(20) atoms. There are three inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one O(1), one O(13), one O(4), one O(5), and two equivalent O(7) atoms to form distorted ZrO6 pentagonal pyramids that share corners with two equivalent Zr(1)O6 pentagonal pyramids,  a cornercorner with one Mg(1)O5 square pyramid, and  an edgeedge with one Mg(1)O5 square pyramid. In the second Zr site, Zr(2) is bonded in a body-centered cubic geometry to one O(11), one O(16), one O(17), one O(8), two equivalent O(12), and two equivalent O(14) atoms. In the third Zr site, Zr(3) is bonded to one O(15), one O(2), one O(20), one O(6), and two equivalent O(18) atoms to form distorted ZrO6 pentagonal pyramids that share corners with two equivalent Zr(3)O6 pentagonal pyramids and  an edgeedge with one Mg(1)O5 square pyramid. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to two equivalent Mg(1), one U(7), and one Zr(1) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to two equivalent U(7) and one Zr(3) atom. In the third O site, O(3) is bonded to one U(2), one U(3), and two equivalent U(4) atoms to form OU4 tetrahedra that share  a cornercorner with one O(10)U4 tetrahedra,  a cornercorner with one O(14)Zr2U2 tetrahedra,  a cornercorner with one O(7)Zr2U2 tetrahedra, corners with two equivalent O(3)U4 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(9)U4 tetrahedra, corners with four equivalent O(11)ZrU3 tetrahedra,  an edgeedge with one O(9)U4 tetrahedra,  an edgeedge with one O(12)Zr2U2 tetrahedra, edges with two equivalent O(17)ZrU3 tetrahedra, and edges with two equivalent O(4)ZrU3 tetrahedra. In the fourth O site, O(4) is bonded to one U(4), two equivalent U(2), and one Zr(1) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(17)ZrU3 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(4)ZrU3 tetrahedra, corners with three equivalent O(11)ZrU3 tetrahedra, corners with four equivalent O(9)U4 tetrahedra,  an edgeedge with one O(11)ZrU3 tetrahedra, edges with two equivalent O(3)U4 tetrahedra, and edges with two equivalent O(7)Zr2U2 tetrahedra. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to two equivalent U(1) and one Zr(1) atom. In the sixth O site, O(6) is bonded in a T-shaped geometry to one Mg(1), one U(1), and one Zr(3) atom. In the seventh O site, O(7) is bonded to one U(1), one U(2), and two equivalent Zr(1) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(12)Zr2U2 tetrahedra, corners with two equivalent O(7)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra,  an edgeedge with one O(9)U4 tetrahedra, and edges with two equivalent O(4)ZrU3 tetrahedra. In the eighth O site, O(8) is bonded to one U(5), two equivalent U(3), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(19)U4 tetrahedra,  a cornercorner with one O(18)Zr2U2 tetrahedra,  a cornercorner with one O(11)ZrU3 tetrahedra, corners with two equivalent O(3)U4 tetrahedra, corners with two equivalent O(15)ZrU3 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(17)ZrU3 tetrahedra, corners with four equivalent O(14)Zr2U2 tetrahedra,  an edgeedge with one O(16)ZrU3 tetrahedra,  an edgeedge with one O(17)ZrU3 tetrahedra, edges with two equivalent O(10)U4 tetrahedra, and edges with two equivalent O(12)Zr2U2 tetrahedra. In the ninth O site, O(9) is bonded to one U(1), one U(2), and two equivalent U(4) atoms to form OU4 tetrahedra that share  a cornercorner with one O(12)Zr2U2 tetrahedra, corners with two equivalent O(9)U4 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(3)U4 tetrahedra, corners with four equivalent O(4)ZrU3 tetrahedra,  an edgeedge with one O(3)U4 tetrahedra,  an edgeedge with one O(7)Zr2U2 tetrahedra, and edges with two equivalent O(11)ZrU3 tetrahedra. In the tenth O site, O(10) is bonded to one U(3), one U(6), and two equivalent U(5) atoms to form OU4 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(12)Zr2U2 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(18)Zr2U2 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(15)ZrU3 tetrahedra, corners with four equivalent O(16)ZrU3 tetrahedra,  an edgeedge with one O(14)Zr2U2 tetrahedra,  an edgeedge with one O(15)ZrU3 tetrahedra, edges with two equivalent O(19)U4 tetrahedra, and edges with two equivalent O(8)ZrU3 tetrahedra. In the eleventh O site, O(11) is bonded to one U(4), two equivalent U(2), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with two equivalent O(7)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra, corners with three equivalent O(4)ZrU3 tetrahedra, corners with four equivalent O(3)U4 tetrahedra,  an edgeedge with one O(17)ZrU3 tetrahedra,  an edgeedge with one O(4)ZrU3 tetrahedra, edges with two equivalent O(9)U4 tetrahedra, and edges with two equivalent O(12)Zr2U2 tetrahedra. In the twelfth O site, O(12) is bonded to one U(2), one U(3), and two equivalent Zr(2) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(10)U4 tetrahedra,  a cornercorner with one O(9)U4 tetrahedra,  a cornercorner with one O(7)Zr2U2 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(16)ZrU3 tetrahedra, corners with two equivalent O(4)ZrU3 tetrahedra, corners with three equivalent O(14)Zr2U2 tetrahedra, corners with four equivalent O(17)ZrU3 tetrahedra,  an edgeedge with one O(3)U4 tetrahedra,  an edgeedge with one O(14)Zr2U2 tetrahedra, edges with two equivalent O(11)ZrU3 tetrahedra, and edges with two equivalent O(8)ZrU3 tetrahedra. In the thirteenth O site, O(13) is bonded in a distorted T-shaped geometry to one Mg(1), two equivalent U(1), and one Zr(1) atom. In the fourteenth O site, O(14) is bonded to one U(3), one U(6), and two equivalent Zr(2) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(15)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra, corners with three equivalent O(12)Zr2U2 tetrahedra, corners with four equivalent O(8)ZrU3 tetrahedra,  an edgeedge with one O(10)U4 tetrahedra,  an edgeedge with one O(12)Zr2U2 tetrahedra, edges with two equivalent O(16)ZrU3 tetrahedra, and edges with two equivalent O(17)ZrU3 tetrahedra. In the fifteenth O site, O(15) is bonded to one U(6), two equivalent U(5), and one Zr(3) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(14)Zr2U2 tetrahedra, corners with two equivalent O(15)ZrU3 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(10)U4 tetrahedra, corners with four equivalent O(19)U4 tetrahedra,  a cornercorner with one O(20)MgZrU2 trigonal pyramid,  an edgeedge with one O(10)U4 tetrahedra, edges with two equivalent O(18)Zr2U2 tetrahedra, and edges with two equivalent O(16)ZrU3 tetrahedra. In the sixteenth O site, O(16) is bonded to one U(5), two equivalent U(6), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(18)Zr2U2 tetrahedra,  a cornercorner with one O(11)ZrU3 tetrahedra,  a cornercorner with one O(17)ZrU3 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(16)ZrU3 tetrahedra, corners with three equivalent O(19)U4 tetrahedra, corners with four equivalent O(10)U4 tetrahedra,  an edgeedge with one O(19)U4 tetrahedra,  an edgeedge with one O(8)ZrU3 tetrahedra, edges with two equivalent O(14)Zr2U2 tetrahedra, and edges with two equivalent O(15)ZrU3 tetrahedra. In the seventeenth O site, O(17) is bonded to one U(4), two equivalent U(3), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(4)ZrU3 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(9)U4 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(8)ZrU3 tetrahedra, corners with four equivalent O(12)Zr2U2 tetrahedra,  an edgeedge with one O(11)ZrU3 tetrahedra,  an edgeedge with one O(8)ZrU3 tetrahedra, edges with two equivalent O(3)U4 tetrahedra, and edges with two equivalent O(14)Zr2U2 tetrahedra. In the eighteenth O site, O(18) is bonded to one U(5), one U(7), and two equivalent Zr(3) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(18)Zr2U2 tetrahedra, corners with four equivalent O(20)MgZrU2 trigonal pyramids,  an edgeedge with one O(19)U4 tetrahedra, and edges with two equivalent O(15)ZrU3 tetrahedra. In the nineteenth O site, O(19) is bonded to one U(5), one U(7), and two equivalent U(6) atoms to form OU4 tetrahedra that share  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with three equivalent O(16)ZrU3 tetrahedra, corners with four equivalent O(15)ZrU3 tetrahedra, corners with two equivalent O(20)MgZrU2 trigonal pyramids,  an edgeedge with one O(18)Zr2U2 tetrahedra,  an edgeedge with one O(16)ZrU3 tetrahedra, and edges with two equivalent O(10)U4 tetrahedra. In the twentieth O site, O(20) is bonded to one Mg(1), two equivalent U(7), and one Zr(3) atom to form distorted OMgZrU2 trigonal pyramids that share  a cornercorner with one O(15)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with four equivalent O(18)Zr2U2 tetrahedra, and corners with two equivalent O(20)MgZrU2 trigonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgZr3U7O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.805
_cell_length_b   6.701
_cell_length_c   17.080
_cell_angle_alpha   98.268
_cell_angle_beta   100.892
_cell_angle_gamma   91.518
_symmetry_Int_Tables_number   1
_cell_volume   422.543
_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
  Mg  Mg0  1  0.332  0.102  0.900  1.0
  Zr  Zr1  1  0.538  0.835  0.764  1.0
  Zr  Zr2  1  0.185  0.405  0.402  1.0
  Zr  Zr3  1  0.389  0.471  0.032  1.0
  U  U4  1  0.994  0.393  0.783  1.0
  U  U5  1  0.859  0.637  0.584  1.0
  U  U6  1  0.704  0.902  0.399  1.0
  U  U7  1  0.350  0.139  0.583  1.0
  U  U8  1  0.054  0.660  0.216  1.0
  U  U9  1  0.560  0.169  0.220  1.0
  U  U10  1  0.921  0.917  0.023  1.0
  O  O11  1  0.812  0.959  0.888  1.0
  O  O12  1  0.389  0.753  0.990  1.0
  O  O13  1  0.817  0.950  0.538  1.0
  O  O14  1  0.411  0.833  0.635  1.0
  O  O15  1  0.528  0.561  0.809  1.0
  O  O16  1  0.131  0.371  0.913  1.0
  O  O17  1  0.994  0.718  0.731  1.0
  O  O18  1  0.165  0.711  0.357  1.0
  O  O19  1  0.893  0.314  0.644  1.0
  O  O20  1  0.592  0.848  0.258  1.0
  O  O21  1  0.312  0.454  0.539  1.0
  O  O22  1  0.740  0.570  0.444  1.0
  O  O23  1  0.356  0.131  0.780  1.0
  O  O24  1  0.672  0.220  0.355  1.0
  O  O25  1  0.507  0.468  0.164  1.0
  O  O26  1  0.102  0.355  0.268  1.0
  O  O27  1  0.245  0.098  0.445  1.0
  O  O28  1  0.932  0.583  0.068  1.0
  O  O29  1  0.014  0.995  0.159  1.0
  O  O30  1  0.475  0.155  0.024  1.0
[/CIF]
.
The material structure described by MgU7Zr3O20 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(13), one O(20), one O(6), and two equivalent O(1) atoms to form distorted MgO5 square pyramids that share  a cornercorner with one Zr(1)O6 pentagonal pyramid, corners with two equivalent Mg(1)O5 square pyramids,  an edgeedge with one Zr(1)O6 pentagonal pyramid, and  an edgeedge with one Zr(3)O6 pentagonal pyramid. There are seven inequivalent U sites. In the first U site, U(1) is bonded in a 7-coordinate geometry to one O(6), one O(7), one O(9), two equivalent O(13), and two equivalent O(5) atoms. In the second U site, U(2) is bonded in a body-centered cubic geometry to one O(12), one O(3), one O(7), one O(9), two equivalent O(11), and two equivalent O(4) atoms. In the third U site, U(3) is bonded in a body-centered cubic geometry to one O(10), one O(12), one O(14), one O(3), two equivalent O(17), and two equivalent O(8) atoms. In the fourth U site, U(4) is bonded in a 7-coordinate geometry to one O(11), one O(17), one O(4), two equivalent O(3), and two equivalent O(9) atoms. In the fifth U site, U(5) is bonded in a body-centered cubic geometry to one O(16), one O(18), one O(19), one O(8), two equivalent O(10), and two equivalent O(15) atoms. In the sixth U site, U(6) is bonded in a 7-coordinate geometry to one O(10), one O(14), one O(15), two equivalent O(16), and two equivalent O(19) atoms. In the seventh U site, U(7) is bonded in a 7-coordinate geometry to one O(1), one O(18), one O(19), two equivalent O(2), and two equivalent O(20) atoms. There are three inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one O(1), one O(13), one O(4), one O(5), and two equivalent O(7) atoms to form distorted ZrO6 pentagonal pyramids that share corners with two equivalent Zr(1)O6 pentagonal pyramids,  a cornercorner with one Mg(1)O5 square pyramid, and  an edgeedge with one Mg(1)O5 square pyramid. In the second Zr site, Zr(2) is bonded in a body-centered cubic geometry to one O(11), one O(16), one O(17), one O(8), two equivalent O(12), and two equivalent O(14) atoms. In the third Zr site, Zr(3) is bonded to one O(15), one O(2), one O(20), one O(6), and two equivalent O(18) atoms to form distorted ZrO6 pentagonal pyramids that share corners with two equivalent Zr(3)O6 pentagonal pyramids and  an edgeedge with one Mg(1)O5 square pyramid. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to two equivalent Mg(1), one U(7), and one Zr(1) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to two equivalent U(7) and one Zr(3) atom. In the third O site, O(3) is bonded to one U(2), one U(3), and two equivalent U(4) atoms to form OU4 tetrahedra that share  a cornercorner with one O(10)U4 tetrahedra,  a cornercorner with one O(14)Zr2U2 tetrahedra,  a cornercorner with one O(7)Zr2U2 tetrahedra, corners with two equivalent O(3)U4 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(9)U4 tetrahedra, corners with four equivalent O(11)ZrU3 tetrahedra,  an edgeedge with one O(9)U4 tetrahedra,  an edgeedge with one O(12)Zr2U2 tetrahedra, edges with two equivalent O(17)ZrU3 tetrahedra, and edges with two equivalent O(4)ZrU3 tetrahedra. In the fourth O site, O(4) is bonded to one U(4), two equivalent U(2), and one Zr(1) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(17)ZrU3 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(4)ZrU3 tetrahedra, corners with three equivalent O(11)ZrU3 tetrahedra, corners with four equivalent O(9)U4 tetrahedra,  an edgeedge with one O(11)ZrU3 tetrahedra, edges with two equivalent O(3)U4 tetrahedra, and edges with two equivalent O(7)Zr2U2 tetrahedra. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to two equivalent U(1) and one Zr(1) atom. In the sixth O site, O(6) is bonded in a T-shaped geometry to one Mg(1), one U(1), and one Zr(3) atom. In the seventh O site, O(7) is bonded to one U(1), one U(2), and two equivalent Zr(1) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(12)Zr2U2 tetrahedra, corners with two equivalent O(7)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra,  an edgeedge with one O(9)U4 tetrahedra, and edges with two equivalent O(4)ZrU3 tetrahedra. In the eighth O site, O(8) is bonded to one U(5), two equivalent U(3), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(19)U4 tetrahedra,  a cornercorner with one O(18)Zr2U2 tetrahedra,  a cornercorner with one O(11)ZrU3 tetrahedra, corners with two equivalent O(3)U4 tetrahedra, corners with two equivalent O(15)ZrU3 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(17)ZrU3 tetrahedra, corners with four equivalent O(14)Zr2U2 tetrahedra,  an edgeedge with one O(16)ZrU3 tetrahedra,  an edgeedge with one O(17)ZrU3 tetrahedra, edges with two equivalent O(10)U4 tetrahedra, and edges with two equivalent O(12)Zr2U2 tetrahedra. In the ninth O site, O(9) is bonded to one U(1), one U(2), and two equivalent U(4) atoms to form OU4 tetrahedra that share  a cornercorner with one O(12)Zr2U2 tetrahedra, corners with two equivalent O(9)U4 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(3)U4 tetrahedra, corners with four equivalent O(4)ZrU3 tetrahedra,  an edgeedge with one O(3)U4 tetrahedra,  an edgeedge with one O(7)Zr2U2 tetrahedra, and edges with two equivalent O(11)ZrU3 tetrahedra. In the tenth O site, O(10) is bonded to one U(3), one U(6), and two equivalent U(5) atoms to form OU4 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(12)Zr2U2 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(18)Zr2U2 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(15)ZrU3 tetrahedra, corners with four equivalent O(16)ZrU3 tetrahedra,  an edgeedge with one O(14)Zr2U2 tetrahedra,  an edgeedge with one O(15)ZrU3 tetrahedra, edges with two equivalent O(19)U4 tetrahedra, and edges with two equivalent O(8)ZrU3 tetrahedra. In the eleventh O site, O(11) is bonded to one U(4), two equivalent U(2), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with two equivalent O(7)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra, corners with three equivalent O(4)ZrU3 tetrahedra, corners with four equivalent O(3)U4 tetrahedra,  an edgeedge with one O(17)ZrU3 tetrahedra,  an edgeedge with one O(4)ZrU3 tetrahedra, edges with two equivalent O(9)U4 tetrahedra, and edges with two equivalent O(12)Zr2U2 tetrahedra. In the twelfth O site, O(12) is bonded to one U(2), one U(3), and two equivalent Zr(2) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(10)U4 tetrahedra,  a cornercorner with one O(9)U4 tetrahedra,  a cornercorner with one O(7)Zr2U2 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(16)ZrU3 tetrahedra, corners with two equivalent O(4)ZrU3 tetrahedra, corners with three equivalent O(14)Zr2U2 tetrahedra, corners with four equivalent O(17)ZrU3 tetrahedra,  an edgeedge with one O(3)U4 tetrahedra,  an edgeedge with one O(14)Zr2U2 tetrahedra, edges with two equivalent O(11)ZrU3 tetrahedra, and edges with two equivalent O(8)ZrU3 tetrahedra. In the thirteenth O site, O(13) is bonded in a distorted T-shaped geometry to one Mg(1), two equivalent U(1), and one Zr(1) atom. In the fourteenth O site, O(14) is bonded to one U(3), one U(6), and two equivalent Zr(2) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(3)U4 tetrahedra,  a cornercorner with one O(15)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with two equivalent O(11)ZrU3 tetrahedra, corners with three equivalent O(12)Zr2U2 tetrahedra, corners with four equivalent O(8)ZrU3 tetrahedra,  an edgeedge with one O(10)U4 tetrahedra,  an edgeedge with one O(12)Zr2U2 tetrahedra, edges with two equivalent O(16)ZrU3 tetrahedra, and edges with two equivalent O(17)ZrU3 tetrahedra. In the fifteenth O site, O(15) is bonded to one U(6), two equivalent U(5), and one Zr(3) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(14)Zr2U2 tetrahedra, corners with two equivalent O(15)ZrU3 tetrahedra, corners with two equivalent O(8)ZrU3 tetrahedra, corners with three equivalent O(10)U4 tetrahedra, corners with four equivalent O(19)U4 tetrahedra,  a cornercorner with one O(20)MgZrU2 trigonal pyramid,  an edgeedge with one O(10)U4 tetrahedra, edges with two equivalent O(18)Zr2U2 tetrahedra, and edges with two equivalent O(16)ZrU3 tetrahedra. In the sixteenth O site, O(16) is bonded to one U(5), two equivalent U(6), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(18)Zr2U2 tetrahedra,  a cornercorner with one O(11)ZrU3 tetrahedra,  a cornercorner with one O(17)ZrU3 tetrahedra, corners with two equivalent O(12)Zr2U2 tetrahedra, corners with two equivalent O(16)ZrU3 tetrahedra, corners with three equivalent O(19)U4 tetrahedra, corners with four equivalent O(10)U4 tetrahedra,  an edgeedge with one O(19)U4 tetrahedra,  an edgeedge with one O(8)ZrU3 tetrahedra, edges with two equivalent O(14)Zr2U2 tetrahedra, and edges with two equivalent O(15)ZrU3 tetrahedra. In the seventeenth O site, O(17) is bonded to one U(4), two equivalent U(3), and one Zr(2) atom to form OZrU3 tetrahedra that share  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(4)ZrU3 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(9)U4 tetrahedra, corners with two equivalent O(17)ZrU3 tetrahedra, corners with three equivalent O(8)ZrU3 tetrahedra, corners with four equivalent O(12)Zr2U2 tetrahedra,  an edgeedge with one O(11)ZrU3 tetrahedra,  an edgeedge with one O(8)ZrU3 tetrahedra, edges with two equivalent O(3)U4 tetrahedra, and edges with two equivalent O(14)Zr2U2 tetrahedra. In the eighteenth O site, O(18) is bonded to one U(5), one U(7), and two equivalent Zr(3) atoms to form OZr2U2 tetrahedra that share  a cornercorner with one O(16)ZrU3 tetrahedra,  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(10)U4 tetrahedra, corners with two equivalent O(18)Zr2U2 tetrahedra, corners with four equivalent O(20)MgZrU2 trigonal pyramids,  an edgeedge with one O(19)U4 tetrahedra, and edges with two equivalent O(15)ZrU3 tetrahedra. In the nineteenth O site, O(19) is bonded to one U(5), one U(7), and two equivalent U(6) atoms to form OU4 tetrahedra that share  a cornercorner with one O(8)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with two equivalent O(14)Zr2U2 tetrahedra, corners with three equivalent O(16)ZrU3 tetrahedra, corners with four equivalent O(15)ZrU3 tetrahedra, corners with two equivalent O(20)MgZrU2 trigonal pyramids,  an edgeedge with one O(18)Zr2U2 tetrahedra,  an edgeedge with one O(16)ZrU3 tetrahedra, and edges with two equivalent O(10)U4 tetrahedra. In the twentieth O site, O(20) is bonded to one Mg(1), two equivalent U(7), and one Zr(3) atom to form distorted OMgZrU2 trigonal pyramids that share  a cornercorner with one O(15)ZrU3 tetrahedra, corners with two equivalent O(19)U4 tetrahedra, corners with four equivalent O(18)Zr2U2 tetrahedra, and corners with two equivalent O(20)MgZrU2 trigonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgZr3U7O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.805
_cell_length_b   6.701
_cell_length_c   17.080
_cell_angle_alpha   98.268
_cell_angle_beta   100.892
_cell_angle_gamma   91.518
_symmetry_Int_Tables_number   1
_cell_volume   422.543
_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
  Mg  Mg0  1  0.332  0.102  0.900  1.0
  Zr  Zr1  1  0.538  0.835  0.764  1.0
  Zr  Zr2  1  0.185  0.405  0.402  1.0
  Zr  Zr3  1  0.389  0.471  0.032  1.0
  U  U4  1  0.994  0.393  0.783  1.0
  U  U5  1  0.859  0.637  0.584  1.0
  U  U6  1  0.704  0.902  0.399  1.0
  U  U7  1  0.350  0.139  0.583  1.0
  U  U8  1  0.054  0.660  0.216  1.0
  U  U9  1  0.560  0.169  0.220  1.0
  U  U10  1  0.921  0.917  0.023  1.0
  O  O11  1  0.812  0.959  0.888  1.0
  O  O12  1  0.389  0.753  0.990  1.0
  O  O13  1  0.817  0.950  0.538  1.0
  O  O14  1  0.411  0.833  0.635  1.0
  O  O15  1  0.528  0.561  0.809  1.0
  O  O16  1  0.131  0.371  0.913  1.0
  O  O17  1  0.994  0.718  0.731  1.0
  O  O18  1  0.165  0.711  0.357  1.0
  O  O19  1  0.893  0.314  0.644  1.0
  O  O20  1  0.592  0.848  0.258  1.0
  O  O21  1  0.312  0.454  0.539  1.0
  O  O22  1  0.740  0.570  0.444  1.0
  O  O23  1  0.356  0.131  0.780  1.0
  O  O24  1  0.672  0.220  0.355  1.0
  O  O25  1  0.507  0.468  0.164  1.0
  O  O26  1  0.102  0.355  0.268  1.0
  O  O27  1  0.245  0.098  0.445  1.0
  O  O28  1  0.932  0.583  0.068  1.0
  O  O29  1  0.014  0.995  0.159  1.0
  O  O30  1  0.475  0.155  0.024  1.0
[/CIF]
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