The structure described by LiSr2SiN3 crystallizes in the monoclinic C2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one N(1), one N(3), one N(4), and one N(7) atom. In the second Li site, Li(2) is bonded in a distorted T-shaped geometry to one N(2), one N(3), and one N(4) atom. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 5-coordinate geometry to one N(1), one N(3), one N(5), one N(6), and one N(7) atom. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to one N(2), one N(3), one N(5), one N(6), and two equivalent N(7) atoms. In the third Sr site, Sr(3) is bonded in a 5-coordinate geometry to one N(4), one N(5), one N(7), and two equivalent N(6) atoms. In the fourth Sr site, Sr(4) is bonded in a 4-coordinate geometry to one N(6), one N(7), and two equivalent N(5) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one N(1), one N(3), one N(4), and one N(5) atom to form corner-sharing SiN4 tetrahedra. In the second Si site, Si(2) is bonded to one N(2), one N(3), one N(4), and one N(6) atom to form corner-sharing SiN4 tetrahedra. There are seven inequivalent N sites. In the first N site, N(1) is bonded in a 6-coordinate geometry to two equivalent Li(1), two equivalent Sr(1), and two equivalent Si(1) atoms. In the second N site, N(2) is bonded in a 4-coordinate geometry to two equivalent Li(2), two equivalent Sr(2), and two equivalent Si(2) atoms. In the third N site, N(3) is bonded in a 6-coordinate geometry to one Li(1), one Li(2), one Sr(1), one Sr(2), one Si(1), and one Si(2) atom. In the fourth N site, N(4) is bonded in a distorted see-saw-like geometry to one Li(1), one Li(2), one Sr(3), one Si(1), and one Si(2) atom. In the fifth N site, N(5) is bonded to one Sr(1), one Sr(2), one Sr(3), two equivalent Sr(4), and one Si(1) atom to form NSr5Si octahedra that share  an edgeedge with one N(5)Sr5Si octahedra, edges with three equivalent N(7)Sr5Li octahedra, and edges with three equivalent N(6)Sr5Si octahedra. In the sixth N site, N(6) is bonded to one Sr(1), one Sr(2), one Sr(4), two equivalent Sr(3), and one Si(2) atom to form distorted NSr5Si octahedra that share corners with four equivalent N(7)Sr5Li octahedra,  an edgeedge with one N(7)Sr5Li octahedra,  an edgeedge with one N(6)Sr5Si octahedra, and edges with three equivalent N(5)Sr5Si octahedra. The corner-sharing octahedral tilt angles range from 5-16°. In the seventh N site, N(7) is bonded to one Li(1), one Sr(1), one Sr(3), one Sr(4), and two equivalent Sr(2) atoms to form distorted NSr5Li octahedra that share corners with four equivalent N(6)Sr5Si octahedra,  an edgeedge with one N(7)Sr5Li octahedra,  an edgeedge with one N(6)Sr5Si octahedra, and edges with three equivalent N(5)Sr5Si octahedra. The corner-sharing octahedral tilt angles range from 5-16°. is represented by the CIF file [CIF]
data_Sr2LiSiN3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.588
_cell_length_b   7.588
_cell_length_c   9.454
_cell_angle_alpha   66.422
_cell_angle_beta   66.422
_cell_angle_gamma   89.646
_symmetry_Int_Tables_number   1
_cell_volume   449.551
_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
  Sr  Sr0  1  0.347  0.588  0.786  1.0
  Sr  Sr1  1  0.845  0.576  0.821  1.0
  Sr  Sr2  1  0.424  0.155  0.179  1.0
  Sr  Sr3  1  0.412  0.653  0.214  1.0
  Sr  Sr4  1  0.318  0.089  0.852  1.0
  Sr  Sr5  1  0.832  0.096  0.843  1.0
  Sr  Sr6  1  0.904  0.168  0.157  1.0
  Sr  Sr7  1  0.911  0.682  0.148  1.0
  Li  Li8  1  0.711  0.480  0.589  1.0
  Li  Li9  1  0.727  0.953  0.547  1.0
  Li  Li10  1  0.520  0.289  0.411  1.0
  Li  Li11  1  0.047  0.273  0.453  1.0
  Si  Si12  1  0.200  0.426  0.597  1.0
  Si  Si13  1  0.202  0.976  0.601  1.0
  Si  Si14  1  0.574  0.800  0.403  1.0
  Si  Si15  1  0.024  0.798  0.399  1.0
  N  N16  1  0.437  0.563  0.500  1.0
  N  N17  1  0.047  0.953  0.500  1.0
  N  N18  1  0.056  0.551  0.493  1.0
  N  N19  1  0.449  0.944  0.507  1.0
  N  N20  1  0.228  0.226  0.551  1.0
  N  N21  1  0.774  0.772  0.449  1.0
  N  N22  1  0.089  0.344  0.821  1.0
  N  N23  1  0.091  0.832  0.822  1.0
  N  N24  1  0.656  0.911  0.179  1.0
  N  N25  1  0.168  0.909  0.178  1.0
  N  N26  1  0.574  0.313  0.847  1.0
  N  N27  1  0.687  0.426  0.153  1.0
[/CIF]
.
The structure described by LiSr2SiN3 crystallizes in the monoclinic C2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one N(1), one N(3), one N(4), and one N(7) atom. In the second Li site, Li(2) is bonded in a distorted T-shaped geometry to one N(2), one N(3), and one N(4) atom. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 5-coordinate geometry to one N(1), one N(3), one N(5), one N(6), and one N(7) atom. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to one N(2), one N(3), one N(5), one N(6), and two equivalent N(7) atoms. In the third Sr site, Sr(3) is bonded in a 5-coordinate geometry to one N(4), one N(5), one N(7), and two equivalent N(6) atoms. In the fourth Sr site, Sr(4) is bonded in a 4-coordinate geometry to one N(6), one N(7), and two equivalent N(5) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one N(1), one N(3), one N(4), and one N(5) atom to form corner-sharing SiN4 tetrahedra. In the second Si site, Si(2) is bonded to one N(2), one N(3), one N(4), and one N(6) atom to form corner-sharing SiN4 tetrahedra. There are seven inequivalent N sites. In the first N site, N(1) is bonded in a 6-coordinate geometry to two equivalent Li(1), two equivalent Sr(1), and two equivalent Si(1) atoms. In the second N site, N(2) is bonded in a 4-coordinate geometry to two equivalent Li(2), two equivalent Sr(2), and two equivalent Si(2) atoms. In the third N site, N(3) is bonded in a 6-coordinate geometry to one Li(1), one Li(2), one Sr(1), one Sr(2), one Si(1), and one Si(2) atom. In the fourth N site, N(4) is bonded in a distorted see-saw-like geometry to one Li(1), one Li(2), one Sr(3), one Si(1), and one Si(2) atom. In the fifth N site, N(5) is bonded to one Sr(1), one Sr(2), one Sr(3), two equivalent Sr(4), and one Si(1) atom to form NSr5Si octahedra that share  an edgeedge with one N(5)Sr5Si octahedra, edges with three equivalent N(7)Sr5Li octahedra, and edges with three equivalent N(6)Sr5Si octahedra. In the sixth N site, N(6) is bonded to one Sr(1), one Sr(2), one Sr(4), two equivalent Sr(3), and one Si(2) atom to form distorted NSr5Si octahedra that share corners with four equivalent N(7)Sr5Li octahedra,  an edgeedge with one N(7)Sr5Li octahedra,  an edgeedge with one N(6)Sr5Si octahedra, and edges with three equivalent N(5)Sr5Si octahedra. The corner-sharing octahedral tilt angles range from 5-16°. In the seventh N site, N(7) is bonded to one Li(1), one Sr(1), one Sr(3), one Sr(4), and two equivalent Sr(2) atoms to form distorted NSr5Li octahedra that share corners with four equivalent N(6)Sr5Si octahedra,  an edgeedge with one N(7)Sr5Li octahedra,  an edgeedge with one N(6)Sr5Si octahedra, and edges with three equivalent N(5)Sr5Si octahedra. The corner-sharing octahedral tilt angles range from 5-16°. is represented by the CIF file [CIF]
data_Sr2LiSiN3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.588
_cell_length_b   7.588
_cell_length_c   9.454
_cell_angle_alpha   66.422
_cell_angle_beta   66.422
_cell_angle_gamma   89.646
_symmetry_Int_Tables_number   1
_cell_volume   449.551
_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
  Sr  Sr0  1  0.347  0.588  0.786  1.0
  Sr  Sr1  1  0.845  0.576  0.821  1.0
  Sr  Sr2  1  0.424  0.155  0.179  1.0
  Sr  Sr3  1  0.412  0.653  0.214  1.0
  Sr  Sr4  1  0.318  0.089  0.852  1.0
  Sr  Sr5  1  0.832  0.096  0.843  1.0
  Sr  Sr6  1  0.904  0.168  0.157  1.0
  Sr  Sr7  1  0.911  0.682  0.148  1.0
  Li  Li8  1  0.711  0.480  0.589  1.0
  Li  Li9  1  0.727  0.953  0.547  1.0
  Li  Li10  1  0.520  0.289  0.411  1.0
  Li  Li11  1  0.047  0.273  0.453  1.0
  Si  Si12  1  0.200  0.426  0.597  1.0
  Si  Si13  1  0.202  0.976  0.601  1.0
  Si  Si14  1  0.574  0.800  0.403  1.0
  Si  Si15  1  0.024  0.798  0.399  1.0
  N  N16  1  0.437  0.563  0.500  1.0
  N  N17  1  0.047  0.953  0.500  1.0
  N  N18  1  0.056  0.551  0.493  1.0
  N  N19  1  0.449  0.944  0.507  1.0
  N  N20  1  0.228  0.226  0.551  1.0
  N  N21  1  0.774  0.772  0.449  1.0
  N  N22  1  0.089  0.344  0.821  1.0
  N  N23  1  0.091  0.832  0.822  1.0
  N  N24  1  0.656  0.911  0.179  1.0
  N  N25  1  0.168  0.909  0.178  1.0
  N  N26  1  0.574  0.313  0.847  1.0
  N  N27  1  0.687  0.426  0.153  1.0
[/CIF]
.