The structure described by Li2Cr2Si4O11 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(2), one O(3), and one O(7) atom. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(6), and one O(9) atom. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(7), one O(8), one O(9), and two equivalent O(11) atoms to form distorted CrO6 octahedra that share  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one Cr(1)O6 octahedra, and edges with two equivalent Cr(2)O5 square pyramids. In the second Cr site, Cr(2) is bonded to one O(11), one O(3), one O(7), one O(8), and one O(9) atom to form distorted CrO5 square pyramids that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and edges with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 76°. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 3°. In the second Si site, Si(2) is bonded to one O(10), one O(11), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 62-66°. In the third Si site, Si(3) is bonded to one O(2), one O(5), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 60°. In the fourth Si site, Si(4) is bonded to one O(10), one O(6), one O(7), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(2)O5 square pyramids,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-70°. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a see-saw-like geometry to one Li(1), one Li(2), one Cr(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Si(1), and one Si(3) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Cr(2), and one Si(1) atom to form distorted edge-sharing OLi2CrSi trigonal pyramids. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(2), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one Si(3), and one Si(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Li(1), one Cr(1), one Cr(2), and one Si(4) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(2), and one Si(3) atom. In the ninth O site, O(9) is bonded to one Li(2), one Cr(1), one Cr(2), and one Si(4) atom to form distorted edge-sharing OLiCr2Si trigonal pyramids. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Cr(2), two equivalent Cr(1), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2Cr2Si4O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.134
_cell_length_b   7.827
_cell_length_c   8.820
_cell_angle_alpha   98.551
_cell_angle_beta   102.041
_cell_angle_gamma   108.535
_symmetry_Int_Tables_number   1
_cell_volume   444.156
_cell_formula_units_Z   2
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  0.379  0.219  0.799  1.0
  Li  Li1  1  0.849  0.255  0.847  1.0
  Li  Li2  1  0.151  0.745  0.153  1.0
  Li  Li3  1  0.621  0.781  0.201  1.0
  Cr  Cr4  1  0.120  0.381  0.614  1.0
  Cr  Cr5  1  0.635  0.386  0.600  1.0
  Cr  Cr6  1  0.365  0.614  0.400  1.0
  Cr  Cr7  1  0.880  0.619  0.386  1.0
  Si  Si8  1  0.757  0.614  0.964  1.0
  Si  Si9  1  0.044  0.780  0.768  1.0
  Si  Si10  1  0.479  0.783  0.781  1.0
  Si  Si11  1  0.225  0.026  0.397  1.0
  Si  Si12  1  0.775  0.974  0.603  1.0
  Si  Si13  1  0.521  0.217  0.219  1.0
  Si  Si14  1  0.956  0.220  0.232  1.0
  Si  Si15  1  0.243  0.386  0.036  1.0
  O  O16  1  0.187  0.378  0.849  1.0
  O  O17  1  0.602  0.736  0.940  1.0
  O  O18  1  0.672  0.410  0.843  1.0
  O  O19  1  0.978  0.743  0.932  1.0
  O  O20  1  0.297  0.851  0.823  1.0
  O  O21  1  0.635  0.961  0.736  1.0
  O  O22  1  0.343  0.186  0.560  1.0
  O  O23  1  0.394  0.601  0.635  1.0
  O  O24  1  0.835  0.188  0.593  1.0
  O  O25  1  0.988  0.950  0.705  1.0
  O  O26  1  0.927  0.593  0.627  1.0
  O  O27  1  0.073  0.407  0.373  1.0
  O  O28  1  0.012  0.050  0.295  1.0
  O  O29  1  0.165  0.812  0.407  1.0
  O  O30  1  0.606  0.399  0.365  1.0
  O  O31  1  0.657  0.814  0.440  1.0
  O  O32  1  0.365  0.039  0.264  1.0
  O  O33  1  0.703  0.149  0.177  1.0
  O  O34  1  0.022  0.257  0.068  1.0
  O  O35  1  0.328  0.590  0.157  1.0
  O  O36  1  0.398  0.264  0.060  1.0
  O  O37  1  0.813  0.622  0.151  1.0
[/CIF]
.
The structure described by Li2Cr2Si4O11 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(2), one O(3), and one O(7) atom. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(6), and one O(9) atom. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(7), one O(8), one O(9), and two equivalent O(11) atoms to form distorted CrO6 octahedra that share  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one Cr(1)O6 octahedra, and edges with two equivalent Cr(2)O5 square pyramids. In the second Cr site, Cr(2) is bonded to one O(11), one O(3), one O(7), one O(8), and one O(9) atom to form distorted CrO5 square pyramids that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and edges with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 76°. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 3°. In the second Si site, Si(2) is bonded to one O(10), one O(11), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 62-66°. In the third Si site, Si(3) is bonded to one O(2), one O(5), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 60°. In the fourth Si site, Si(4) is bonded to one O(10), one O(6), one O(7), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(2)O5 square pyramids,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-70°. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a see-saw-like geometry to one Li(1), one Li(2), one Cr(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Si(1), and one Si(3) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Cr(2), and one Si(1) atom to form distorted edge-sharing OLi2CrSi trigonal pyramids. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(2), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one Si(3), and one Si(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Li(1), one Cr(1), one Cr(2), and one Si(4) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(2), and one Si(3) atom. In the ninth O site, O(9) is bonded to one Li(2), one Cr(1), one Cr(2), and one Si(4) atom to form distorted edge-sharing OLiCr2Si trigonal pyramids. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Cr(2), two equivalent Cr(1), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2Cr2Si4O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.134
_cell_length_b   7.827
_cell_length_c   8.820
_cell_angle_alpha   98.551
_cell_angle_beta   102.041
_cell_angle_gamma   108.535
_symmetry_Int_Tables_number   1
_cell_volume   444.156
_cell_formula_units_Z   2
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  0.379  0.219  0.799  1.0
  Li  Li1  1  0.849  0.255  0.847  1.0
  Li  Li2  1  0.151  0.745  0.153  1.0
  Li  Li3  1  0.621  0.781  0.201  1.0
  Cr  Cr4  1  0.120  0.381  0.614  1.0
  Cr  Cr5  1  0.635  0.386  0.600  1.0
  Cr  Cr6  1  0.365  0.614  0.400  1.0
  Cr  Cr7  1  0.880  0.619  0.386  1.0
  Si  Si8  1  0.757  0.614  0.964  1.0
  Si  Si9  1  0.044  0.780  0.768  1.0
  Si  Si10  1  0.479  0.783  0.781  1.0
  Si  Si11  1  0.225  0.026  0.397  1.0
  Si  Si12  1  0.775  0.974  0.603  1.0
  Si  Si13  1  0.521  0.217  0.219  1.0
  Si  Si14  1  0.956  0.220  0.232  1.0
  Si  Si15  1  0.243  0.386  0.036  1.0
  O  O16  1  0.187  0.378  0.849  1.0
  O  O17  1  0.602  0.736  0.940  1.0
  O  O18  1  0.672  0.410  0.843  1.0
  O  O19  1  0.978  0.743  0.932  1.0
  O  O20  1  0.297  0.851  0.823  1.0
  O  O21  1  0.635  0.961  0.736  1.0
  O  O22  1  0.343  0.186  0.560  1.0
  O  O23  1  0.394  0.601  0.635  1.0
  O  O24  1  0.835  0.188  0.593  1.0
  O  O25  1  0.988  0.950  0.705  1.0
  O  O26  1  0.927  0.593  0.627  1.0
  O  O27  1  0.073  0.407  0.373  1.0
  O  O28  1  0.012  0.050  0.295  1.0
  O  O29  1  0.165  0.812  0.407  1.0
  O  O30  1  0.606  0.399  0.365  1.0
  O  O31  1  0.657  0.814  0.440  1.0
  O  O32  1  0.365  0.039  0.264  1.0
  O  O33  1  0.703  0.149  0.177  1.0
  O  O34  1  0.022  0.257  0.068  1.0
  O  O35  1  0.328  0.590  0.157  1.0
  O  O36  1  0.398  0.264  0.060  1.0
  O  O37  1  0.813  0.622  0.151  1.0
[/CIF]
.