The compound described by MgTl4Al4O12 is Esseneite-like structured and crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(11), one O(2), and one O(9) atom to form distorted MgO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra, corners with two equivalent Tl(3)O4 tetrahedra, corners with two equivalent Al(2)O4 tetrahedra, and  an edgeedge with one Al(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 28°. There are four inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 6-coordinate geometry to one O(10), one O(12), one O(2), one O(3), one O(4), and one O(7) atom. In the second Tl site, Tl(2) is bonded in a 6-coordinate geometry to one O(12), one O(3), one O(4), one O(5), one O(7), and one O(8) atom. In the third Tl site, Tl(3) is bonded to one O(1), one O(6), one O(8), and one O(9) atom to form distorted TlO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(3)O6 octahedra,  a cornercorner with one Al(4)O4 tetrahedra, and corners with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 74-78°. In the fourth Tl site, Tl(4) is bonded in a 3-coordinate geometry to one O(1), one O(10), and one O(6) atom. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(10), one O(12), one O(3), one O(4), and one O(8) atom to form AlO6 octahedra that share corners with four equivalent Al(3)O6 octahedra,  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Al(2)O4 tetrahedra, and corners with two equivalent Tl(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-35°. In the second Al site, Al(2) is bonded to one O(11), one O(12), one O(2), and one O(5) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra, and corners with two equivalent Al(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. In the third Al site, Al(3) is bonded to one O(10), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form distorted AlO6 octahedra that share corners with four equivalent Al(1)O6 octahedra,  a cornercorner with one Al(4)O4 tetrahedra, and corners with two equivalent Tl(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-35°. In the fourth Al site, Al(4) is bonded to one O(11), one O(5), one O(7), and one O(9) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(3)O6 octahedra,  a cornercorner with one Tl(3)O4 tetrahedra, corners with two equivalent Al(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 42°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Tl(3), one Tl(4), and one Al(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Tl(1), and one Al(2) atom. In the third O site, O(3) is bonded to one Tl(1), one Tl(2), one Al(1), and one Al(3) atom to form a mixture of distorted corner and edge-sharing OAl2Tl2 trigonal pyramids. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Tl(1), one Tl(2), one Al(1), and one Al(3) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Tl(2), one Al(2), and one Al(4) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Tl(3), one Tl(4), and one Al(3) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Tl(1), one Tl(2), one Al(3), and one Al(4) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Tl(2), one Tl(3), one Al(1), and one Al(3) atom. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Mg(1), one Tl(3), and one Al(4) atom. In the tenth O site, O(10) is bonded to one Tl(1), one Tl(4), one Al(1), and one Al(3) atom to form distorted corner-sharing OAl2Tl2 tetrahedra. In the eleventh O site, O(11) is bonded in a distorted T-shaped geometry to one Mg(1), one Al(2), and one Al(4) atom. In the twelfth O site, O(12) is bonded to one Tl(1), one Tl(2), one Al(1), and one Al(2) atom to form a mixture of distorted corner and edge-sharing OAl2Tl2 trigonal pyramids. is represented by the CIF file [CIF]
data_MgAl4Tl4O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.461
_cell_length_b   5.500
_cell_length_c   9.511
_cell_angle_alpha   74.790
_cell_angle_beta   86.602
_cell_angle_gamma   87.638
_symmetry_Int_Tables_number   1
_cell_volume   275.088
_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  0.955  0.241  0.398  1.0
  Al  Al1  1  0.002  0.479  0.986  1.0
  Al  Al2  1  0.065  0.637  0.603  1.0
  Al  Al3  1  0.490  0.947  0.984  1.0
  Al  Al4  1  0.565  0.025  0.570  1.0
  Tl  Tl5  1  0.013  0.065  0.786  1.0
  Tl  Tl6  1  0.525  0.494  0.804  1.0
  Tl  Tl7  1  0.469  0.412  0.192  1.0
  Tl  Tl8  1  0.948  0.860  0.215  1.0
  O  O9  1  0.063  0.385  0.188  1.0
  O  O10  1  0.095  0.344  0.559  1.0
  O  O11  1  0.236  0.203  0.945  1.0
  O  O12  1  0.287  0.714  0.925  1.0
  O  O13  1  0.355  0.775  0.606  1.0
  O  O14  1  0.445  0.812  0.178  1.0
  O  O15  1  0.588  0.114  0.741  1.0
  O  O16  1  0.700  0.273  0.026  1.0
  O  O17  1  0.590  0.273  0.411  1.0
  O  O18  1  0.806  0.792  0.972  1.0
  O  O19  1  0.866  0.893  0.534  1.0
  O  O20  1  0.936  0.524  0.785  1.0
[/CIF]
.
The compound described by MgTl4Al4O12 is Esseneite-like structured and crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(11), one O(2), and one O(9) atom to form distorted MgO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra, corners with two equivalent Tl(3)O4 tetrahedra, corners with two equivalent Al(2)O4 tetrahedra, and  an edgeedge with one Al(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 28°. There are four inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 6-coordinate geometry to one O(10), one O(12), one O(2), one O(3), one O(4), and one O(7) atom. In the second Tl site, Tl(2) is bonded in a 6-coordinate geometry to one O(12), one O(3), one O(4), one O(5), one O(7), and one O(8) atom. In the third Tl site, Tl(3) is bonded to one O(1), one O(6), one O(8), and one O(9) atom to form distorted TlO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(3)O6 octahedra,  a cornercorner with one Al(4)O4 tetrahedra, and corners with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 74-78°. In the fourth Tl site, Tl(4) is bonded in a 3-coordinate geometry to one O(1), one O(10), and one O(6) atom. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(10), one O(12), one O(3), one O(4), and one O(8) atom to form AlO6 octahedra that share corners with four equivalent Al(3)O6 octahedra,  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Al(2)O4 tetrahedra, and corners with two equivalent Tl(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-35°. In the second Al site, Al(2) is bonded to one O(11), one O(12), one O(2), and one O(5) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra, and corners with two equivalent Al(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. In the third Al site, Al(3) is bonded to one O(10), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form distorted AlO6 octahedra that share corners with four equivalent Al(1)O6 octahedra,  a cornercorner with one Al(4)O4 tetrahedra, and corners with two equivalent Tl(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-35°. In the fourth Al site, Al(4) is bonded to one O(11), one O(5), one O(7), and one O(9) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(3)O6 octahedra,  a cornercorner with one Tl(3)O4 tetrahedra, corners with two equivalent Al(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 42°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Tl(3), one Tl(4), and one Al(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Tl(1), and one Al(2) atom. In the third O site, O(3) is bonded to one Tl(1), one Tl(2), one Al(1), and one Al(3) atom to form a mixture of distorted corner and edge-sharing OAl2Tl2 trigonal pyramids. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Tl(1), one Tl(2), one Al(1), and one Al(3) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Tl(2), one Al(2), and one Al(4) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Tl(3), one Tl(4), and one Al(3) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Tl(1), one Tl(2), one Al(3), and one Al(4) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Tl(2), one Tl(3), one Al(1), and one Al(3) atom. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Mg(1), one Tl(3), and one Al(4) atom. In the tenth O site, O(10) is bonded to one Tl(1), one Tl(4), one Al(1), and one Al(3) atom to form distorted corner-sharing OAl2Tl2 tetrahedra. In the eleventh O site, O(11) is bonded in a distorted T-shaped geometry to one Mg(1), one Al(2), and one Al(4) atom. In the twelfth O site, O(12) is bonded to one Tl(1), one Tl(2), one Al(1), and one Al(2) atom to form a mixture of distorted corner and edge-sharing OAl2Tl2 trigonal pyramids. is represented by the CIF file [CIF]
data_MgAl4Tl4O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.461
_cell_length_b   5.500
_cell_length_c   9.511
_cell_angle_alpha   74.790
_cell_angle_beta   86.602
_cell_angle_gamma   87.638
_symmetry_Int_Tables_number   1
_cell_volume   275.088
_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  0.955  0.241  0.398  1.0
  Al  Al1  1  0.002  0.479  0.986  1.0
  Al  Al2  1  0.065  0.637  0.603  1.0
  Al  Al3  1  0.490  0.947  0.984  1.0
  Al  Al4  1  0.565  0.025  0.570  1.0
  Tl  Tl5  1  0.013  0.065  0.786  1.0
  Tl  Tl6  1  0.525  0.494  0.804  1.0
  Tl  Tl7  1  0.469  0.412  0.192  1.0
  Tl  Tl8  1  0.948  0.860  0.215  1.0
  O  O9  1  0.063  0.385  0.188  1.0
  O  O10  1  0.095  0.344  0.559  1.0
  O  O11  1  0.236  0.203  0.945  1.0
  O  O12  1  0.287  0.714  0.925  1.0
  O  O13  1  0.355  0.775  0.606  1.0
  O  O14  1  0.445  0.812  0.178  1.0
  O  O15  1  0.588  0.114  0.741  1.0
  O  O16  1  0.700  0.273  0.026  1.0
  O  O17  1  0.590  0.273  0.411  1.0
  O  O18  1  0.806  0.792  0.972  1.0
  O  O19  1  0.866  0.893  0.534  1.0
  O  O20  1  0.936  0.524  0.785  1.0
[/CIF]
.