The structure described by Li2Nb3MnO8 is Spinel-derived structured and crystallizes in the trigonal R3m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1) and three equivalent O(2) atoms to form LiO4 tetrahedra that share corners with three equivalent Li(2)O6 octahedra and corners with nine equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-59°. In the second Li site, Li(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form LiO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent Mn(1)O4 tetrahedra, and edges with six equivalent Nb(1)O6 octahedra. Nb(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent Mn(1)O4 tetrahedra, edges with two equivalent Li(2)O6 octahedra, and edges with four equivalent Nb(1)O6 octahedra. Mn(1) is bonded to one O(4) and three equivalent O(3) atoms to form MnO4 tetrahedra that share corners with three equivalent Li(2)O6 octahedra and corners with nine equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 59-63°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Li(1) and three equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Li(1), one Li(2), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded to one Li(2), two equivalent Nb(1), and one Mn(1) atom to form distorted OLiMnNb2 trigonal pyramids that share  a cornercorner with one O(4)MnNb3 trigonal pyramid, corners with two equivalent O(3)LiMnNb2 trigonal pyramids,  an edgeedge with one O(4)MnNb3 trigonal pyramid, and edges with two equivalent O(3)LiMnNb2 trigonal pyramids. In the fourth O site, O(4) is bonded to three equivalent Nb(1) and one Mn(1) atom to form a mixture of distorted corner and edge-sharing OMnNb3 trigonal pyramids. is represented by the CIF card [CIF]
data_Li2MnNb3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.240
_cell_length_b   6.240
_cell_length_c   6.240
_cell_angle_alpha   59.071
_cell_angle_beta   59.071
_cell_angle_gamma   59.071
_symmetry_Int_Tables_number   1
_cell_volume   168.126
_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  0.119  0.119  0.119  1.0
  Li  Li1  1  0.504  0.504  0.504  1.0
  Mn  Mn2  1  0.875  0.875  0.875  1.0
  Nb  Nb3  1  0.022  0.489  0.489  1.0
  Nb  Nb4  1  0.489  0.022  0.489  1.0
  Nb  Nb5  1  0.489  0.489  0.022  1.0
  O  O6  1  0.247  0.247  0.247  1.0
  O  O7  1  0.254  0.254  0.724  1.0
  O  O8  1  0.254  0.724  0.254  1.0
  O  O9  1  0.724  0.254  0.254  1.0
  O  O10  1  0.287  0.748  0.748  1.0
  O  O11  1  0.748  0.287  0.748  1.0
  O  O12  1  0.748  0.748  0.287  1.0
  O  O13  1  0.739  0.739  0.739  1.0
[/CIF]
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The structure described by Li2Nb3MnO8 is Spinel-derived structured and crystallizes in the trigonal R3m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1) and three equivalent O(2) atoms to form LiO4 tetrahedra that share corners with three equivalent Li(2)O6 octahedra and corners with nine equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-59°. In the second Li site, Li(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form LiO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent Mn(1)O4 tetrahedra, and edges with six equivalent Nb(1)O6 octahedra. Nb(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent Mn(1)O4 tetrahedra, edges with two equivalent Li(2)O6 octahedra, and edges with four equivalent Nb(1)O6 octahedra. Mn(1) is bonded to one O(4) and three equivalent O(3) atoms to form MnO4 tetrahedra that share corners with three equivalent Li(2)O6 octahedra and corners with nine equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 59-63°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Li(1) and three equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Li(1), one Li(2), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded to one Li(2), two equivalent Nb(1), and one Mn(1) atom to form distorted OLiMnNb2 trigonal pyramids that share  a cornercorner with one O(4)MnNb3 trigonal pyramid, corners with two equivalent O(3)LiMnNb2 trigonal pyramids,  an edgeedge with one O(4)MnNb3 trigonal pyramid, and edges with two equivalent O(3)LiMnNb2 trigonal pyramids. In the fourth O site, O(4) is bonded to three equivalent Nb(1) and one Mn(1) atom to form a mixture of distorted corner and edge-sharing OMnNb3 trigonal pyramids. is represented by the CIF card [CIF]
data_Li2MnNb3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.240
_cell_length_b   6.240
_cell_length_c   6.240
_cell_angle_alpha   59.071
_cell_angle_beta   59.071
_cell_angle_gamma   59.071
_symmetry_Int_Tables_number   1
_cell_volume   168.126
_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  0.119  0.119  0.119  1.0
  Li  Li1  1  0.504  0.504  0.504  1.0
  Mn  Mn2  1  0.875  0.875  0.875  1.0
  Nb  Nb3  1  0.022  0.489  0.489  1.0
  Nb  Nb4  1  0.489  0.022  0.489  1.0
  Nb  Nb5  1  0.489  0.489  0.022  1.0
  O  O6  1  0.247  0.247  0.247  1.0
  O  O7  1  0.254  0.254  0.724  1.0
  O  O8  1  0.254  0.724  0.254  1.0
  O  O9  1  0.724  0.254  0.254  1.0
  O  O10  1  0.287  0.748  0.748  1.0
  O  O11  1  0.748  0.287  0.748  1.0
  O  O12  1  0.748  0.748  0.287  1.0
  O  O13  1  0.739  0.739  0.739  1.0
[/CIF]
.