The structure described by Li4SnSe4 is Aluminum carbonitride-like structured and crystallizes in the orthorhombic Pnma space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form distorted LiSe6 octahedra that share corners with two equivalent Li(3)Se4 tetrahedra, corners with two equivalent Sn(1)Se4 tetrahedra, corners with six equivalent Li(2)Se4 tetrahedra, edges with two equivalent Li(1)Se6 octahedra, edges with two equivalent Li(3)Se4 tetrahedra, edges with two equivalent Sn(1)Se4 tetrahedra, and faces with two equivalent Li(2)Se4 tetrahedra. In the second Li site, Li(2) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form distorted LiSe4 tetrahedra that share corners with three equivalent Li(1)Se6 octahedra, corners with four equivalent Li(2)Se4 tetrahedra, corners with four equivalent Li(3)Se4 tetrahedra, corners with four equivalent Sn(1)Se4 tetrahedra, and  a faceface with one Li(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 14-49°. In the third Li site, Li(3) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form distorted LiSe4 tetrahedra that share corners with two equivalent Li(1)Se6 octahedra, corners with two equivalent Sn(1)Se4 tetrahedra, corners with eight equivalent Li(2)Se4 tetrahedra, edges with two equivalent Li(1)Se6 octahedra, and  an edgeedge with one Sn(1)Se4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. Sn(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form distorted SnSe4 tetrahedra that share corners with two equivalent Li(1)Se6 octahedra, corners with two equivalent Li(3)Se4 tetrahedra, corners with eight equivalent Li(2)Se4 tetrahedra, edges with two equivalent Li(1)Se6 octahedra, and  an edgeedge with one Li(3)Se4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. There are three inequivalent Se sites. In the first Se site, Se(3) is bonded in a 6-coordinate geometry to one Li(3), two equivalent Li(1), two equivalent Li(2), and one Sn(1) atom. In the second Se site, Se(1) is bonded in a 6-coordinate geometry to one Li(3), two equivalent Li(1), two equivalent Li(2), and one Sn(1) atom. In the third Se site, Se(2) is bonded to one Li(1), one Li(3), two equivalent Li(2), and one Sn(1) atom to form distorted corner-sharing SeLi4Sn trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li4SnSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.658
_cell_length_b   8.278
_cell_length_c   14.933
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   823.114
_cell_formula_units_Z   4
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  0.000  0.500  0.500  1.0
  Li  Li1  1  0.500  0.000  0.000  1.0
  Li  Li2  1  0.000  0.000  0.500  1.0
  Li  Li3  1  0.500  0.500  0.000  1.0
  Li  Li4  1  0.822  0.496  0.677  1.0
  Li  Li5  1  0.678  0.004  0.177  1.0
  Li  Li6  1  0.178  0.996  0.323  1.0
  Li  Li7  1  0.322  0.504  0.823  1.0
  Li  Li8  1  0.178  0.504  0.323  1.0
  Li  Li9  1  0.322  0.996  0.823  1.0
  Li  Li10  1  0.822  0.004  0.677  1.0
  Li  Li11  1  0.678  0.496  0.177  1.0
  Li  Li12  1  0.380  0.750  0.588  1.0
  Li  Li13  1  0.120  0.750  0.088  1.0
  Li  Li14  1  0.620  0.250  0.412  1.0
  Li  Li15  1  0.880  0.250  0.912  1.0
  Sn  Sn16  1  0.643  0.750  0.408  1.0
  Sn  Sn17  1  0.857  0.750  0.908  1.0
  Sn  Sn18  1  0.357  0.250  0.592  1.0
  Sn  Sn19  1  0.143  0.250  0.092  1.0
  Se  Se20  1  0.770  0.750  0.570  1.0
  Se  Se21  1  0.730  0.750  0.070  1.0
  Se  Se22  1  0.230  0.250  0.430  1.0
  Se  Se23  1  0.270  0.250  0.930  1.0
  Se  Se24  1  0.786  0.497  0.339  1.0
  Se  Se25  1  0.714  0.003  0.839  1.0
  Se  Se26  1  0.214  0.997  0.661  1.0
  Se  Se27  1  0.286  0.503  0.161  1.0
  Se  Se28  1  0.214  0.503  0.661  1.0
  Se  Se29  1  0.286  0.997  0.161  1.0
  Se  Se30  1  0.786  0.003  0.339  1.0
  Se  Se31  1  0.714  0.497  0.839  1.0
  Se  Se32  1  0.264  0.750  0.418  1.0
  Se  Se33  1  0.236  0.750  0.918  1.0
  Se  Se34  1  0.736  0.250  0.582  1.0
  Se  Se35  1  0.764  0.250  0.082  1.0
[/CIF]
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The structure described by Li4SnSe4 is Aluminum carbonitride-like structured and crystallizes in the orthorhombic Pnma space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form distorted LiSe6 octahedra that share corners with two equivalent Li(3)Se4 tetrahedra, corners with two equivalent Sn(1)Se4 tetrahedra, corners with six equivalent Li(2)Se4 tetrahedra, edges with two equivalent Li(1)Se6 octahedra, edges with two equivalent Li(3)Se4 tetrahedra, edges with two equivalent Sn(1)Se4 tetrahedra, and faces with two equivalent Li(2)Se4 tetrahedra. In the second Li site, Li(2) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form distorted LiSe4 tetrahedra that share corners with three equivalent Li(1)Se6 octahedra, corners with four equivalent Li(2)Se4 tetrahedra, corners with four equivalent Li(3)Se4 tetrahedra, corners with four equivalent Sn(1)Se4 tetrahedra, and  a faceface with one Li(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 14-49°. In the third Li site, Li(3) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form distorted LiSe4 tetrahedra that share corners with two equivalent Li(1)Se6 octahedra, corners with two equivalent Sn(1)Se4 tetrahedra, corners with eight equivalent Li(2)Se4 tetrahedra, edges with two equivalent Li(1)Se6 octahedra, and  an edgeedge with one Sn(1)Se4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. Sn(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form distorted SnSe4 tetrahedra that share corners with two equivalent Li(1)Se6 octahedra, corners with two equivalent Li(3)Se4 tetrahedra, corners with eight equivalent Li(2)Se4 tetrahedra, edges with two equivalent Li(1)Se6 octahedra, and  an edgeedge with one Li(3)Se4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. There are three inequivalent Se sites. In the first Se site, Se(3) is bonded in a 6-coordinate geometry to one Li(3), two equivalent Li(1), two equivalent Li(2), and one Sn(1) atom. In the second Se site, Se(1) is bonded in a 6-coordinate geometry to one Li(3), two equivalent Li(1), two equivalent Li(2), and one Sn(1) atom. In the third Se site, Se(2) is bonded to one Li(1), one Li(3), two equivalent Li(2), and one Sn(1) atom to form distorted corner-sharing SeLi4Sn trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li4SnSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.658
_cell_length_b   8.278
_cell_length_c   14.933
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   823.114
_cell_formula_units_Z   4
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  0.000  0.500  0.500  1.0
  Li  Li1  1  0.500  0.000  0.000  1.0
  Li  Li2  1  0.000  0.000  0.500  1.0
  Li  Li3  1  0.500  0.500  0.000  1.0
  Li  Li4  1  0.822  0.496  0.677  1.0
  Li  Li5  1  0.678  0.004  0.177  1.0
  Li  Li6  1  0.178  0.996  0.323  1.0
  Li  Li7  1  0.322  0.504  0.823  1.0
  Li  Li8  1  0.178  0.504  0.323  1.0
  Li  Li9  1  0.322  0.996  0.823  1.0
  Li  Li10  1  0.822  0.004  0.677  1.0
  Li  Li11  1  0.678  0.496  0.177  1.0
  Li  Li12  1  0.380  0.750  0.588  1.0
  Li  Li13  1  0.120  0.750  0.088  1.0
  Li  Li14  1  0.620  0.250  0.412  1.0
  Li  Li15  1  0.880  0.250  0.912  1.0
  Sn  Sn16  1  0.643  0.750  0.408  1.0
  Sn  Sn17  1  0.857  0.750  0.908  1.0
  Sn  Sn18  1  0.357  0.250  0.592  1.0
  Sn  Sn19  1  0.143  0.250  0.092  1.0
  Se  Se20  1  0.770  0.750  0.570  1.0
  Se  Se21  1  0.730  0.750  0.070  1.0
  Se  Se22  1  0.230  0.250  0.430  1.0
  Se  Se23  1  0.270  0.250  0.930  1.0
  Se  Se24  1  0.786  0.497  0.339  1.0
  Se  Se25  1  0.714  0.003  0.839  1.0
  Se  Se26  1  0.214  0.997  0.661  1.0
  Se  Se27  1  0.286  0.503  0.161  1.0
  Se  Se28  1  0.214  0.503  0.661  1.0
  Se  Se29  1  0.286  0.997  0.161  1.0
  Se  Se30  1  0.786  0.003  0.339  1.0
  Se  Se31  1  0.714  0.497  0.839  1.0
  Se  Se32  1  0.264  0.750  0.418  1.0
  Se  Se33  1  0.236  0.750  0.918  1.0
  Se  Se34  1  0.736  0.250  0.582  1.0
  Se  Se35  1  0.764  0.250  0.082  1.0
[/CIF]
.