The material structure described by Li16Ta2N8O crystallizes in the trigonal R-3 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one N(2) and three equivalent N(1) atoms to form distorted LiN4 tetrahedra that share corners with three equivalent Li(2)N3O tetrahedra, corners with three equivalent Li(3)N3O tetrahedra, corners with four equivalent Ta(1)N4 tetrahedra, corners with six equivalent Li(4)N4 tetrahedra, edges with three equivalent Li(3)N3O tetrahedra, and edges with three equivalent Li(4)N4 tetrahedra. In the second Li site, Li(2) is bonded to three equivalent N(1) and one O(1) atom to form distorted LiN3O tetrahedra that share  a cornercorner with one Li(2)N3O tetrahedra, corners with three equivalent Li(3)N3O tetrahedra, corners with three equivalent Li(1)N4 tetrahedra, corners with three equivalent Ta(1)N4 tetrahedra, corners with six equivalent Li(4)N4 tetrahedra, edges with three equivalent Li(3)N3O tetrahedra, and edges with three equivalent Li(4)N4 tetrahedra. In the third Li site, Li(3) is bonded to one N(1), two equivalent N(2), and one O(1) atom to form distorted LiN3O tetrahedra that share  a cornercorner with one Li(2)N3O tetrahedra,  a cornercorner with one Li(1)N4 tetrahedra,  a cornercorner with one Ta(1)N4 tetrahedra, corners with four equivalent Li(4)N4 tetrahedra, corners with nine equivalent Li(3)N3O tetrahedra,  an edgeedge with one Li(2)N3O tetrahedra,  an edgeedge with one Li(1)N4 tetrahedra,  an edgeedge with one Ta(1)N4 tetrahedra, and edges with three equivalent Li(3)N3O tetrahedra. In the fourth Li site, Li(4) is bonded to four equivalent N(1) atoms to form distorted LiN4 tetrahedra that share corners with two equivalent Li(2)N3O tetrahedra, corners with two equivalent Li(1)N4 tetrahedra, corners with two equivalent Ta(1)N4 tetrahedra, corners with four equivalent Li(3)N3O tetrahedra, corners with six equivalent Li(4)N4 tetrahedra,  an edgeedge with one Li(2)N3O tetrahedra,  an edgeedge with one Li(1)N4 tetrahedra,  an edgeedge with one Ta(1)N4 tetrahedra, and edges with three equivalent Li(4)N4 tetrahedra. Ta(1) is bonded to one N(2) and three equivalent N(1) atoms to form TaN4 tetrahedra that share corners with three equivalent Li(2)N3O tetrahedra, corners with three equivalent Li(3)N3O tetrahedra, corners with four equivalent Li(1)N4 tetrahedra, corners with six equivalent Li(4)N4 tetrahedra, edges with three equivalent Li(3)N3O tetrahedra, and edges with three equivalent Li(4)N4 tetrahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted body-centered cubic geometry to one Li(1), one Li(2), one Li(3), four equivalent Li(4), and one Ta(1) atom. In the second N site, N(2) is bonded in a distorted body-centered cubic geometry to one Li(1), six equivalent Li(3), and one Ta(1) atom. O(1) is bonded in a body-centered cubic geometry to two equivalent Li(2) and six equivalent Li(3) atoms. is represented by the CIF file [CIF]
data_Li16Ta2N8O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.199
_cell_length_b   9.199
_cell_length_c   9.199
_cell_angle_alpha   38.066
_cell_angle_beta   38.066
_cell_angle_gamma   38.066
_symmetry_Int_Tables_number   1
_cell_volume   265.685
_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  0.417  0.417  0.417  1.0
  Li  Li1  1  0.583  0.583  0.583  1.0
  Li  Li2  1  0.078  0.078  0.078  1.0
  Li  Li3  1  0.922  0.922  0.922  1.0
  Li  Li4  1  0.682  0.057  0.331  1.0
  Li  Li5  1  0.057  0.331  0.682  1.0
  Li  Li6  1  0.331  0.682  0.057  1.0
  Li  Li7  1  0.318  0.943  0.669  1.0
  Li  Li8  1  0.943  0.669  0.318  1.0
  Li  Li9  1  0.669  0.318  0.943  1.0
  Li  Li10  1  0.174  0.833  0.419  1.0
  Li  Li11  1  0.581  0.826  0.167  1.0
  Li  Li12  1  0.167  0.581  0.826  1.0
  Li  Li13  1  0.826  0.167  0.581  1.0
  Li  Li14  1  0.419  0.174  0.833  1.0
  Li  Li15  1  0.833  0.419  0.174  1.0
  Ta  Ta16  1  0.249  0.249  0.249  1.0
  Ta  Ta17  1  0.751  0.751  0.751  1.0
  N  N18  1  0.226  0.913  0.535  1.0
  N  N19  1  0.326  0.326  0.326  1.0
  N  N20  1  0.674  0.674  0.674  1.0
  N  N21  1  0.913  0.535  0.226  1.0
  N  N22  1  0.535  0.226  0.913  1.0
  N  N23  1  0.465  0.774  0.087  1.0
  N  N24  1  0.087  0.465  0.774  1.0
  N  N25  1  0.774  0.087  0.465  1.0
  O  O26  1  0.000  0.000  0.000  1.0
[/CIF]
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The material structure described by Li16Ta2N8O crystallizes in the trigonal R-3 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one N(2) and three equivalent N(1) atoms to form distorted LiN4 tetrahedra that share corners with three equivalent Li(2)N3O tetrahedra, corners with three equivalent Li(3)N3O tetrahedra, corners with four equivalent Ta(1)N4 tetrahedra, corners with six equivalent Li(4)N4 tetrahedra, edges with three equivalent Li(3)N3O tetrahedra, and edges with three equivalent Li(4)N4 tetrahedra. In the second Li site, Li(2) is bonded to three equivalent N(1) and one O(1) atom to form distorted LiN3O tetrahedra that share  a cornercorner with one Li(2)N3O tetrahedra, corners with three equivalent Li(3)N3O tetrahedra, corners with three equivalent Li(1)N4 tetrahedra, corners with three equivalent Ta(1)N4 tetrahedra, corners with six equivalent Li(4)N4 tetrahedra, edges with three equivalent Li(3)N3O tetrahedra, and edges with three equivalent Li(4)N4 tetrahedra. In the third Li site, Li(3) is bonded to one N(1), two equivalent N(2), and one O(1) atom to form distorted LiN3O tetrahedra that share  a cornercorner with one Li(2)N3O tetrahedra,  a cornercorner with one Li(1)N4 tetrahedra,  a cornercorner with one Ta(1)N4 tetrahedra, corners with four equivalent Li(4)N4 tetrahedra, corners with nine equivalent Li(3)N3O tetrahedra,  an edgeedge with one Li(2)N3O tetrahedra,  an edgeedge with one Li(1)N4 tetrahedra,  an edgeedge with one Ta(1)N4 tetrahedra, and edges with three equivalent Li(3)N3O tetrahedra. In the fourth Li site, Li(4) is bonded to four equivalent N(1) atoms to form distorted LiN4 tetrahedra that share corners with two equivalent Li(2)N3O tetrahedra, corners with two equivalent Li(1)N4 tetrahedra, corners with two equivalent Ta(1)N4 tetrahedra, corners with four equivalent Li(3)N3O tetrahedra, corners with six equivalent Li(4)N4 tetrahedra,  an edgeedge with one Li(2)N3O tetrahedra,  an edgeedge with one Li(1)N4 tetrahedra,  an edgeedge with one Ta(1)N4 tetrahedra, and edges with three equivalent Li(4)N4 tetrahedra. Ta(1) is bonded to one N(2) and three equivalent N(1) atoms to form TaN4 tetrahedra that share corners with three equivalent Li(2)N3O tetrahedra, corners with three equivalent Li(3)N3O tetrahedra, corners with four equivalent Li(1)N4 tetrahedra, corners with six equivalent Li(4)N4 tetrahedra, edges with three equivalent Li(3)N3O tetrahedra, and edges with three equivalent Li(4)N4 tetrahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted body-centered cubic geometry to one Li(1), one Li(2), one Li(3), four equivalent Li(4), and one Ta(1) atom. In the second N site, N(2) is bonded in a distorted body-centered cubic geometry to one Li(1), six equivalent Li(3), and one Ta(1) atom. O(1) is bonded in a body-centered cubic geometry to two equivalent Li(2) and six equivalent Li(3) atoms. is represented by the CIF file [CIF]
data_Li16Ta2N8O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.199
_cell_length_b   9.199
_cell_length_c   9.199
_cell_angle_alpha   38.066
_cell_angle_beta   38.066
_cell_angle_gamma   38.066
_symmetry_Int_Tables_number   1
_cell_volume   265.685
_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  0.417  0.417  0.417  1.0
  Li  Li1  1  0.583  0.583  0.583  1.0
  Li  Li2  1  0.078  0.078  0.078  1.0
  Li  Li3  1  0.922  0.922  0.922  1.0
  Li  Li4  1  0.682  0.057  0.331  1.0
  Li  Li5  1  0.057  0.331  0.682  1.0
  Li  Li6  1  0.331  0.682  0.057  1.0
  Li  Li7  1  0.318  0.943  0.669  1.0
  Li  Li8  1  0.943  0.669  0.318  1.0
  Li  Li9  1  0.669  0.318  0.943  1.0
  Li  Li10  1  0.174  0.833  0.419  1.0
  Li  Li11  1  0.581  0.826  0.167  1.0
  Li  Li12  1  0.167  0.581  0.826  1.0
  Li  Li13  1  0.826  0.167  0.581  1.0
  Li  Li14  1  0.419  0.174  0.833  1.0
  Li  Li15  1  0.833  0.419  0.174  1.0
  Ta  Ta16  1  0.249  0.249  0.249  1.0
  Ta  Ta17  1  0.751  0.751  0.751  1.0
  N  N18  1  0.226  0.913  0.535  1.0
  N  N19  1  0.326  0.326  0.326  1.0
  N  N20  1  0.674  0.674  0.674  1.0
  N  N21  1  0.913  0.535  0.226  1.0
  N  N22  1  0.535  0.226  0.913  1.0
  N  N23  1  0.465  0.774  0.087  1.0
  N  N24  1  0.087  0.465  0.774  1.0
  N  N25  1  0.774  0.087  0.465  1.0
  O  O26  1  0.000  0.000  0.000  1.0
[/CIF]
.