The structure described by Li12Mn2O9 crystallizes in the triclinic P1 space group. There are twelve inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra, corners with three equivalent Li(6)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(5)O4 tetrahedra,  an edgeedge with one Li(8)O4 tetrahedra,  an edgeedge with one Li(9)O4 tetrahedra,  an edgeedge with one Mn(2)O4 tetrahedra, and  an edgeedge with one Li(12)O4 trigonal pyramid. In the second Li site, Li(2) is bonded to one O(1), one O(5), one O(8), and one O(9) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(7)O4 tetrahedra, corners with three equivalent Li(3)O4 trigonal pyramids,  an edgeedge with one Li(10)O4 tetrahedra,  an edgeedge with one Li(11)O4 tetrahedra,  an edgeedge with one Li(5)O4 tetrahedra, and  an edgeedge with one Mn(2)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(2), one O(5), one O(8), and one O(9) atom to form distorted LiO4 trigonal pyramids that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, corners with three equivalent Li(7)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  an edgeedge with one Li(10)O4 tetrahedra,  an edgeedge with one Li(11)O4 tetrahedra,  an edgeedge with one Li(5)O4 tetrahedra, and  an edgeedge with one Mn(2)O4 tetrahedra. In the fourth Li site, Li(4) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra, corners with three equivalent Mn(1)O4 tetrahedra,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(10)O4 tetrahedra,  an edgeedge with one Li(11)O4 tetrahedra,  an edgeedge with one Li(8)O4 tetrahedra,  an edgeedge with one Li(9)O4 tetrahedra, and  an edgeedge with one Li(12)O4 trigonal pyramid. In the fifth Li site, Li(5) is bonded to one O(3), one O(5), one O(8), and one O(9) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra, corners with three equivalent Mn(2)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(1)O4 tetrahedra,  an edgeedge with one Li(2)O4 tetrahedra,  an edgeedge with one Li(6)O4 tetrahedra,  an edgeedge with one Li(7)O4 tetrahedra, and  an edgeedge with one Li(3)O4 trigonal pyramid. In the sixth Li site, Li(6) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(5)O4 tetrahedra,  an edgeedge with one Li(8)O4 tetrahedra,  an edgeedge with one Li(9)O4 tetrahedra,  an edgeedge with one Mn(2)O4 tetrahedra, and  an edgeedge with one Li(12)O4 trigonal pyramid. In the seventh Li site, Li(7) is bonded to one O(5), one O(6), one O(8), and one O(9) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, corners with three equivalent Li(3)O4 trigonal pyramids,  an edgeedge with one Li(10)O4 tetrahedra,  an edgeedge with one Li(11)O4 tetrahedra,  an edgeedge with one Li(5)O4 tetrahedra, and  an edgeedge with one Mn(2)O4 tetrahedra. In the eighth Li site, Li(8) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(9)O4 tetrahedra, corners with three equivalent Li(12)O4 trigonal pyramids,  an edgeedge with one Li(1)O4 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra,  an edgeedge with one Li(6)O4 tetrahedra, and  an edgeedge with one Mn(1)O4 tetrahedra. In the ninth Li site, Li(9) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(8)O4 tetrahedra, corners with three equivalent Li(12)O4 trigonal pyramids,  an edgeedge with one Li(1)O4 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra,  an edgeedge with one Li(6)O4 tetrahedra, and  an edgeedge with one Mn(1)O4 tetrahedra. In the tenth Li site, Li(10) is bonded to one O(1), one O(2), one O(6), and one O(8) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(11)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  an edgeedge with one Li(2)O4 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra,  an edgeedge with one Li(7)O4 tetrahedra,  an edgeedge with one Mn(1)O4 tetrahedra, and  an edgeedge with one Li(3)O4 trigonal pyramid. In the eleventh Li site, Li(11) is bonded to one O(1), one O(2), one O(6), and one O(9) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(10)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  an edgeedge with one Li(2)O4 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra,  an edgeedge with one Li(7)O4 tetrahedra,  an edgeedge with one Mn(1)O4 tetrahedra, and  an edgeedge with one Li(3)O4 trigonal pyramid. In the twelfth Li site, Li(12) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form distorted LiO4 trigonal pyramids that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(8)O4 tetrahedra, corners with three equivalent Li(9)O4 tetrahedra,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(1)O4 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra,  an edgeedge with one Li(6)O4 tetrahedra, and  an edgeedge with one Mn(1)O4 tetrahedra. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form MnO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(10)O4 tetrahedra,  an edgeedge with one Li(11)O4 tetrahedra,  an edgeedge with one Li(8)O4 tetrahedra,  an edgeedge with one Li(9)O4 tetrahedra, and  an edgeedge with one Li(12)O4 trigonal pyramid. In the second Mn site, Mn(2) is bonded to one O(5), one O(7), one O(8), and one O(9) atom to form MnO4 tetrahedra that share  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra, corners with three equivalent Li(5)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(1)O4 tetrahedra,  an edgeedge with one Li(2)O4 tetrahedra,  an edgeedge with one Li(6)O4 tetrahedra,  an edgeedge with one Li(7)O4 tetrahedra, and  an edgeedge with one Li(3)O4 trigonal pyramid. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Li(10), one Li(11), one Li(2), one Li(4), one Li(8), and one Mn(1) atom. In the second O site, O(2) is bonded to one Li(10), one Li(11), one Li(12), one Li(3), one Li(4), and one Mn(1) atom to form OLi5Mn octahedra that share  a cornercorner with one O(7)Li5Mn pentagonal pyramid,  an edgeedge with one O(8)Li6Mn hexagonal pyramid, and  an edgeedge with one O(3)Li7 hexagonal pyramid. In the third O site, O(3) is bonded to one Li(1), one Li(12), one Li(4), one Li(5), one Li(6), one Li(8), and one Li(9) atom to form distorted OLi7 hexagonal pyramids that share  a cornercorner with one O(7)Li5Mn pentagonal pyramid,  an edgeedge with one O(8)Li6Mn hexagonal pyramid,  an edgeedge with one O(2)Li5Mn octahedra, and edges with two equivalent O(7)Li5Mn pentagonal pyramids. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Li(1), one Li(12), one Li(6), one Li(8), one Li(9), and one Mn(1) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Li(2), one Li(3), one Li(5), one Li(6), one Li(7), and one Mn(2) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Li(10), one Li(11), one Li(4), one Li(7), one Li(9), and one Mn(1) atom. In the seventh O site, O(7) is bonded to one Li(1), one Li(12), one Li(6), one Li(8), one Li(9), and one Mn(2) atom to form distorted OLi5Mn pentagonal pyramids that share  a cornercorner with one O(3)Li7 hexagonal pyramid,  a cornercorner with one O(2)Li5Mn octahedra,  an edgeedge with one O(8)Li6Mn hexagonal pyramid, and edges with two equivalent O(3)Li7 hexagonal pyramids. The corner-sharing octahedral tilt angles are 65°. In the eighth O site, O(8) is bonded to one Li(1), one Li(10), one Li(2), one Li(3), one Li(5), one Li(7), and one Mn(2) atom to form distorted OLi6Mn hexagonal pyramids that share  an edgeedge with one O(3)Li7 hexagonal pyramid,  an edgeedge with one O(2)Li5Mn octahedra, and  an edgeedge with one O(7)Li5Mn pentagonal pyramid. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Li(11), one Li(2), one Li(3), one Li(5), one Li(7), and one Mn(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li12Mn2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.764
_cell_length_b   5.674
_cell_length_c   8.162
_cell_angle_alpha   87.151
_cell_angle_beta   92.246
_cell_angle_gamma   117.821
_symmetry_Int_Tables_number   1
_cell_volume   235.795
_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
  Li  Li0  1  0.060  0.700  0.919  1.0
  Li  Li1  1  0.288  0.953  0.580  1.0
  Li  Li2  1  0.064  0.346  0.573  1.0
  Li  Li3  1  0.037  0.027  0.261  1.0
  Li  Li4  1  0.971  0.997  0.772  1.0
  Li  Li5  1  0.321  0.366  0.918  1.0
  Li  Li6  1  0.625  0.681  0.583  1.0
  Li  Li7  1  0.376  0.035  0.089  1.0
  Li  Li8  1  0.704  0.714  0.069  1.0
  Li  Li9  1  0.924  0.622  0.403  1.0
  Li  Li10  1  0.669  0.069  0.397  1.0
  Li  Li11  1  0.939  0.293  0.078  1.0
  Mn  Mn12  1  0.331  0.620  0.273  1.0
  Mn  Mn13  1  0.669  0.301  0.759  1.0
  O  O14  1  0.292  0.920  0.348  1.0
  O  O15  1  0.995  0.344  0.323  1.0
  O  O16  1  0.039  0.020  0.008  1.0
  O  O17  1  0.325  0.648  0.037  1.0
  O  O18  1  0.334  0.286  0.683  1.0
  O  O19  1  0.687  0.746  0.326  1.0
  O  O20  1  0.677  0.383  0.979  1.0
  O  O21  1  0.958  0.639  0.669  1.0
  O  O22  1  0.701  0.047  0.634  1.0
[/CIF]
.
The structure described by Li12Mn2O9 crystallizes in the triclinic P1 space group. There are twelve inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra, corners with three equivalent Li(6)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(5)O4 tetrahedra,  an edgeedge with one Li(8)O4 tetrahedra,  an edgeedge with one Li(9)O4 tetrahedra,  an edgeedge with one Mn(2)O4 tetrahedra, and  an edgeedge with one Li(12)O4 trigonal pyramid. In the second Li site, Li(2) is bonded to one O(1), one O(5), one O(8), and one O(9) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(7)O4 tetrahedra, corners with three equivalent Li(3)O4 trigonal pyramids,  an edgeedge with one Li(10)O4 tetrahedra,  an edgeedge with one Li(11)O4 tetrahedra,  an edgeedge with one Li(5)O4 tetrahedra, and  an edgeedge with one Mn(2)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(2), one O(5), one O(8), and one O(9) atom to form distorted LiO4 trigonal pyramids that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, corners with three equivalent Li(7)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  an edgeedge with one Li(10)O4 tetrahedra,  an edgeedge with one Li(11)O4 tetrahedra,  an edgeedge with one Li(5)O4 tetrahedra, and  an edgeedge with one Mn(2)O4 tetrahedra. In the fourth Li site, Li(4) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra, corners with three equivalent Mn(1)O4 tetrahedra,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(10)O4 tetrahedra,  an edgeedge with one Li(11)O4 tetrahedra,  an edgeedge with one Li(8)O4 tetrahedra,  an edgeedge with one Li(9)O4 tetrahedra, and  an edgeedge with one Li(12)O4 trigonal pyramid. In the fifth Li site, Li(5) is bonded to one O(3), one O(5), one O(8), and one O(9) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra, corners with three equivalent Mn(2)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(1)O4 tetrahedra,  an edgeedge with one Li(2)O4 tetrahedra,  an edgeedge with one Li(6)O4 tetrahedra,  an edgeedge with one Li(7)O4 tetrahedra, and  an edgeedge with one Li(3)O4 trigonal pyramid. In the sixth Li site, Li(6) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(5)O4 tetrahedra,  an edgeedge with one Li(8)O4 tetrahedra,  an edgeedge with one Li(9)O4 tetrahedra,  an edgeedge with one Mn(2)O4 tetrahedra, and  an edgeedge with one Li(12)O4 trigonal pyramid. In the seventh Li site, Li(7) is bonded to one O(5), one O(6), one O(8), and one O(9) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, corners with three equivalent Li(3)O4 trigonal pyramids,  an edgeedge with one Li(10)O4 tetrahedra,  an edgeedge with one Li(11)O4 tetrahedra,  an edgeedge with one Li(5)O4 tetrahedra, and  an edgeedge with one Mn(2)O4 tetrahedra. In the eighth Li site, Li(8) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(9)O4 tetrahedra, corners with three equivalent Li(12)O4 trigonal pyramids,  an edgeedge with one Li(1)O4 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra,  an edgeedge with one Li(6)O4 tetrahedra, and  an edgeedge with one Mn(1)O4 tetrahedra. In the ninth Li site, Li(9) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(8)O4 tetrahedra, corners with three equivalent Li(12)O4 trigonal pyramids,  an edgeedge with one Li(1)O4 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra,  an edgeedge with one Li(6)O4 tetrahedra, and  an edgeedge with one Mn(1)O4 tetrahedra. In the tenth Li site, Li(10) is bonded to one O(1), one O(2), one O(6), and one O(8) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(11)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  an edgeedge with one Li(2)O4 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra,  an edgeedge with one Li(7)O4 tetrahedra,  an edgeedge with one Mn(1)O4 tetrahedra, and  an edgeedge with one Li(3)O4 trigonal pyramid. In the eleventh Li site, Li(11) is bonded to one O(1), one O(2), one O(6), and one O(9) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(10)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  an edgeedge with one Li(2)O4 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra,  an edgeedge with one Li(7)O4 tetrahedra,  an edgeedge with one Mn(1)O4 tetrahedra, and  an edgeedge with one Li(3)O4 trigonal pyramid. In the twelfth Li site, Li(12) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form distorted LiO4 trigonal pyramids that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(5)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with three equivalent Li(8)O4 tetrahedra, corners with three equivalent Li(9)O4 tetrahedra,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(1)O4 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra,  an edgeedge with one Li(6)O4 tetrahedra, and  an edgeedge with one Mn(1)O4 tetrahedra. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form MnO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(6)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(10)O4 tetrahedra,  an edgeedge with one Li(11)O4 tetrahedra,  an edgeedge with one Li(8)O4 tetrahedra,  an edgeedge with one Li(9)O4 tetrahedra, and  an edgeedge with one Li(12)O4 trigonal pyramid. In the second Mn site, Mn(2) is bonded to one O(5), one O(7), one O(8), and one O(9) atom to form MnO4 tetrahedra that share  a cornercorner with one Li(10)O4 tetrahedra,  a cornercorner with one Li(11)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one Li(8)O4 tetrahedra,  a cornercorner with one Li(9)O4 tetrahedra, corners with three equivalent Li(5)O4 tetrahedra,  a cornercorner with one Li(12)O4 trigonal pyramid,  a cornercorner with one Li(3)O4 trigonal pyramid,  an edgeedge with one Li(1)O4 tetrahedra,  an edgeedge with one Li(2)O4 tetrahedra,  an edgeedge with one Li(6)O4 tetrahedra,  an edgeedge with one Li(7)O4 tetrahedra, and  an edgeedge with one Li(3)O4 trigonal pyramid. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Li(10), one Li(11), one Li(2), one Li(4), one Li(8), and one Mn(1) atom. In the second O site, O(2) is bonded to one Li(10), one Li(11), one Li(12), one Li(3), one Li(4), and one Mn(1) atom to form OLi5Mn octahedra that share  a cornercorner with one O(7)Li5Mn pentagonal pyramid,  an edgeedge with one O(8)Li6Mn hexagonal pyramid, and  an edgeedge with one O(3)Li7 hexagonal pyramid. In the third O site, O(3) is bonded to one Li(1), one Li(12), one Li(4), one Li(5), one Li(6), one Li(8), and one Li(9) atom to form distorted OLi7 hexagonal pyramids that share  a cornercorner with one O(7)Li5Mn pentagonal pyramid,  an edgeedge with one O(8)Li6Mn hexagonal pyramid,  an edgeedge with one O(2)Li5Mn octahedra, and edges with two equivalent O(7)Li5Mn pentagonal pyramids. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Li(1), one Li(12), one Li(6), one Li(8), one Li(9), and one Mn(1) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Li(2), one Li(3), one Li(5), one Li(6), one Li(7), and one Mn(2) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Li(10), one Li(11), one Li(4), one Li(7), one Li(9), and one Mn(1) atom. In the seventh O site, O(7) is bonded to one Li(1), one Li(12), one Li(6), one Li(8), one Li(9), and one Mn(2) atom to form distorted OLi5Mn pentagonal pyramids that share  a cornercorner with one O(3)Li7 hexagonal pyramid,  a cornercorner with one O(2)Li5Mn octahedra,  an edgeedge with one O(8)Li6Mn hexagonal pyramid, and edges with two equivalent O(3)Li7 hexagonal pyramids. The corner-sharing octahedral tilt angles are 65°. In the eighth O site, O(8) is bonded to one Li(1), one Li(10), one Li(2), one Li(3), one Li(5), one Li(7), and one Mn(2) atom to form distorted OLi6Mn hexagonal pyramids that share  an edgeedge with one O(3)Li7 hexagonal pyramid,  an edgeedge with one O(2)Li5Mn octahedra, and  an edgeedge with one O(7)Li5Mn pentagonal pyramid. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Li(11), one Li(2), one Li(3), one Li(5), one Li(7), and one Mn(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li12Mn2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.764
_cell_length_b   5.674
_cell_length_c   8.162
_cell_angle_alpha   87.151
_cell_angle_beta   92.246
_cell_angle_gamma   117.821
_symmetry_Int_Tables_number   1
_cell_volume   235.795
_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
  Li  Li0  1  0.060  0.700  0.919  1.0
  Li  Li1  1  0.288  0.953  0.580  1.0
  Li  Li2  1  0.064  0.346  0.573  1.0
  Li  Li3  1  0.037  0.027  0.261  1.0
  Li  Li4  1  0.971  0.997  0.772  1.0
  Li  Li5  1  0.321  0.366  0.918  1.0
  Li  Li6  1  0.625  0.681  0.583  1.0
  Li  Li7  1  0.376  0.035  0.089  1.0
  Li  Li8  1  0.704  0.714  0.069  1.0
  Li  Li9  1  0.924  0.622  0.403  1.0
  Li  Li10  1  0.669  0.069  0.397  1.0
  Li  Li11  1  0.939  0.293  0.078  1.0
  Mn  Mn12  1  0.331  0.620  0.273  1.0
  Mn  Mn13  1  0.669  0.301  0.759  1.0
  O  O14  1  0.292  0.920  0.348  1.0
  O  O15  1  0.995  0.344  0.323  1.0
  O  O16  1  0.039  0.020  0.008  1.0
  O  O17  1  0.325  0.648  0.037  1.0
  O  O18  1  0.334  0.286  0.683  1.0
  O  O19  1  0.687  0.746  0.326  1.0
  O  O20  1  0.677  0.383  0.979  1.0
  O  O21  1  0.958  0.639  0.669  1.0
  O  O22  1  0.701  0.047  0.634  1.0
[/CIF]
.