The compound described by Li9Cr5(SiO8)2 is Caswellsilverite-derived structured and crystallizes in the monoclinic P2/m space group. There are six inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form LiO6 octahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with four equivalent Si(1)O6 octahedra,  an edgeedge with one Li(1)O6 octahedra,  an edgeedge with one Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(5)O6 octahedra, edges with two equivalent Li(6)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-10°. In the second Li site, Li(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form LiO6 octahedra that share corners with two equivalent Si(1)O6 octahedra, corners with four equivalent Cr(3)O6 octahedra,  an edgeedge with one Li(1)O6 octahedra,  an edgeedge with one Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(4)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, and edges with two equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-6°. In the third Li site, Li(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form LiO6 octahedra that share corners with two equivalent Li(5)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra,  an edgeedge with one Li(4)O6 octahedra,  an edgeedge with one Li(6)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, and edges with two equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-15°. In the fourth Li site, Li(4) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form LiO6 octahedra that share corners with two equivalent Cr(2)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, edges with four equivalent Li(2)O6 octahedra, and edges with four equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles are 5°. In the fifth Li site, Li(5) is bonded to two equivalent O(5) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with two equivalent Li(6)O6 octahedra, corners with four equivalent Li(3)O6 octahedra, edges with two equivalent Li(6)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 13-15°. In the sixth Li site, Li(6) is bonded to two equivalent O(5) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with two equivalent Li(5)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(5)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 13-15°. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CrO6 octahedra that share corners with two equivalent Li(3)O6 octahedra, corners with two equivalent Li(4)O6 octahedra, corners with two equivalent Li(6)O6 octahedra,  an edgeedge with one Li(5)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, and edges with two equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. In the second Cr site, Cr(2) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with two equivalent Li(4)O6 octahedra, corners with four equivalent Li(3)O6 octahedra, edges with two equivalent Li(4)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with four equivalent Li(2)O6 octahedra, and edges with four equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. In the third Cr site, Cr(3) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Li(2)O6 octahedra,  an edgeedge with one Cr(3)O6 octahedra,  an edgeedge with one Si(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(4)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-10°. Si(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form SiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Li(1)O6 octahedra,  an edgeedge with one Cr(3)O6 octahedra,  an edgeedge with one Si(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(5)O6 octahedra, edges with two equivalent Li(6)O6 octahedra, and edges with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-9°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(3), one Li(5), one Li(6), one Cr(1), and one Si(1) atom to form distorted OLi4CrSi octahedra that share corners with two equivalent O(2)Li3Cr3 octahedra, corners with four equivalent O(1)Li4CrSi octahedra,  an edgeedge with one O(2)Li3Cr3 octahedra, edges with three equivalent O(1)Li4CrSi octahedra, edges with four equivalent O(3)Li3Cr2Si octahedra, and edges with four equivalent O(5)Li4Si2 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the second O site, O(2) is bonded to one Li(2), one Li(3), one Li(4), one Cr(1), one Cr(2), and one Cr(3) atom to form OLi3Cr3 octahedra that share corners with two equivalent O(1)Li4CrSi octahedra, corners with four equivalent O(2)Li3Cr3 octahedra,  an edgeedge with one O(1)Li4CrSi octahedra, edges with three equivalent O(2)Li3Cr3 octahedra, edges with four equivalent O(3)Li3Cr2Si octahedra, and edges with four equivalent O(4)Li3Cr3 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Li(3), one Cr(1), one Cr(3), and one Si(1) atom to form OLi3Cr2Si octahedra that share corners with two equivalent O(3)Li3Cr2Si octahedra, corners with two equivalent O(4)Li3Cr3 octahedra, corners with two equivalent O(5)Li4Si2 octahedra,  an edgeedge with one O(4)Li3Cr3 octahedra,  an edgeedge with one O(5)Li4Si2 octahedra, edges with two equivalent O(3)Li3Cr2Si octahedra, edges with four equivalent O(2)Li3Cr3 octahedra, and edges with four equivalent O(1)Li4CrSi octahedra. The corner-sharing octahedral tilt angles range from 2-5°. In the fourth O site, O(4) is bonded to one Li(4), two equivalent Li(2), one Cr(2), and two equivalent Cr(3) atoms to form OLi3Cr3 octahedra that share corners with two equivalent O(4)Li3Cr3 octahedra, corners with four equivalent O(3)Li3Cr2Si octahedra, edges with two equivalent O(3)Li3Cr2Si octahedra, edges with two equivalent O(4)Li3Cr3 octahedra, and edges with eight equivalent O(2)Li3Cr3 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the fifth O site, O(5) is bonded to one Li(5), one Li(6), two equivalent Li(1), and two equivalent Si(1) atoms to form OLi4Si2 octahedra that share corners with two equivalent O(5)Li4Si2 octahedra, corners with four equivalent O(3)Li3Cr2Si octahedra, edges with two equivalent O(3)Li3Cr2Si octahedra, edges with two equivalent O(5)Li4Si2 octahedra, and edges with eight equivalent O(1)Li4CrSi octahedra. The corner-sharing octahedral tilt angles range from 0-3°. is represented by the CIF card [CIF]
data_Li9Cr5(SiO8)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.549
_cell_length_b   5.051
_cell_length_c   5.069
_cell_angle_alpha   70.715
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   279.069
_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  0.383  0.000  0.000  1.0
  Li  Li1  1  0.124  0.000  0.000  1.0
  Li  Li2  1  0.257  0.500  0.000  1.0
  Li  Li3  1  0.876  0.000  0.000  1.0
  Li  Li4  1  0.000  0.500  0.000  1.0
  Li  Li5  1  0.617  0.000  0.000  1.0
  Li  Li6  1  0.743  0.500  0.000  1.0
  Li  Li7  1  0.500  0.000  0.500  1.0
  Li  Li8  1  0.500  0.500  0.000  1.0
  Cr  Cr9  1  0.259  0.000  0.500  1.0
  Cr  Cr10  1  0.000  0.000  0.500  1.0
  Cr  Cr11  1  0.130  0.500  0.500  1.0
  Cr  Cr12  1  0.741  0.000  0.500  1.0
  Cr  Cr13  1  0.870  0.500  0.500  1.0
  Si  Si14  1  0.383  0.500  0.500  1.0
  Si  Si15  1  0.617  0.500  0.500  1.0
  O  O16  1  0.375  0.722  0.712  1.0
  O  O17  1  0.128  0.759  0.728  1.0
  O  O18  1  0.265  0.730  0.281  1.0
  O  O19  1  0.000  0.739  0.272  1.0
  O  O20  1  0.265  0.270  0.719  1.0
  O  O21  1  0.872  0.759  0.728  1.0
  O  O22  1  0.375  0.278  0.288  1.0
  O  O23  1  0.000  0.261  0.728  1.0
  O  O24  1  0.625  0.722  0.712  1.0
  O  O25  1  0.735  0.730  0.281  1.0
  O  O26  1  0.128  0.241  0.272  1.0
  O  O27  1  0.872  0.241  0.272  1.0
  O  O28  1  0.735  0.270  0.719  1.0
  O  O29  1  0.500  0.707  0.286  1.0
  O  O30  1  0.625  0.278  0.288  1.0
  O  O31  1  0.500  0.293  0.714  1.0
[/CIF]
.
The compound described by Li9Cr5(SiO8)2 is Caswellsilverite-derived structured and crystallizes in the monoclinic P2/m space group. There are six inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form LiO6 octahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with four equivalent Si(1)O6 octahedra,  an edgeedge with one Li(1)O6 octahedra,  an edgeedge with one Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(5)O6 octahedra, edges with two equivalent Li(6)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-10°. In the second Li site, Li(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form LiO6 octahedra that share corners with two equivalent Si(1)O6 octahedra, corners with four equivalent Cr(3)O6 octahedra,  an edgeedge with one Li(1)O6 octahedra,  an edgeedge with one Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(4)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, and edges with two equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-6°. In the third Li site, Li(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form LiO6 octahedra that share corners with two equivalent Li(5)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra,  an edgeedge with one Li(4)O6 octahedra,  an edgeedge with one Li(6)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, and edges with two equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-15°. In the fourth Li site, Li(4) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form LiO6 octahedra that share corners with two equivalent Cr(2)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, edges with four equivalent Li(2)O6 octahedra, and edges with four equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles are 5°. In the fifth Li site, Li(5) is bonded to two equivalent O(5) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with two equivalent Li(6)O6 octahedra, corners with four equivalent Li(3)O6 octahedra, edges with two equivalent Li(6)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 13-15°. In the sixth Li site, Li(6) is bonded to two equivalent O(5) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with two equivalent Li(5)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(5)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 13-15°. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CrO6 octahedra that share corners with two equivalent Li(3)O6 octahedra, corners with two equivalent Li(4)O6 octahedra, corners with two equivalent Li(6)O6 octahedra,  an edgeedge with one Li(5)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, and edges with two equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. In the second Cr site, Cr(2) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with two equivalent Li(4)O6 octahedra, corners with four equivalent Li(3)O6 octahedra, edges with two equivalent Li(4)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with four equivalent Li(2)O6 octahedra, and edges with four equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. In the third Cr site, Cr(3) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Li(2)O6 octahedra,  an edgeedge with one Cr(3)O6 octahedra,  an edgeedge with one Si(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(4)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-10°. Si(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form SiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Li(1)O6 octahedra,  an edgeedge with one Cr(3)O6 octahedra,  an edgeedge with one Si(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Li(5)O6 octahedra, edges with two equivalent Li(6)O6 octahedra, and edges with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-9°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(3), one Li(5), one Li(6), one Cr(1), and one Si(1) atom to form distorted OLi4CrSi octahedra that share corners with two equivalent O(2)Li3Cr3 octahedra, corners with four equivalent O(1)Li4CrSi octahedra,  an edgeedge with one O(2)Li3Cr3 octahedra, edges with three equivalent O(1)Li4CrSi octahedra, edges with four equivalent O(3)Li3Cr2Si octahedra, and edges with four equivalent O(5)Li4Si2 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the second O site, O(2) is bonded to one Li(2), one Li(3), one Li(4), one Cr(1), one Cr(2), and one Cr(3) atom to form OLi3Cr3 octahedra that share corners with two equivalent O(1)Li4CrSi octahedra, corners with four equivalent O(2)Li3Cr3 octahedra,  an edgeedge with one O(1)Li4CrSi octahedra, edges with three equivalent O(2)Li3Cr3 octahedra, edges with four equivalent O(3)Li3Cr2Si octahedra, and edges with four equivalent O(4)Li3Cr3 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Li(3), one Cr(1), one Cr(3), and one Si(1) atom to form OLi3Cr2Si octahedra that share corners with two equivalent O(3)Li3Cr2Si octahedra, corners with two equivalent O(4)Li3Cr3 octahedra, corners with two equivalent O(5)Li4Si2 octahedra,  an edgeedge with one O(4)Li3Cr3 octahedra,  an edgeedge with one O(5)Li4Si2 octahedra, edges with two equivalent O(3)Li3Cr2Si octahedra, edges with four equivalent O(2)Li3Cr3 octahedra, and edges with four equivalent O(1)Li4CrSi octahedra. The corner-sharing octahedral tilt angles range from 2-5°. In the fourth O site, O(4) is bonded to one Li(4), two equivalent Li(2), one Cr(2), and two equivalent Cr(3) atoms to form OLi3Cr3 octahedra that share corners with two equivalent O(4)Li3Cr3 octahedra, corners with four equivalent O(3)Li3Cr2Si octahedra, edges with two equivalent O(3)Li3Cr2Si octahedra, edges with two equivalent O(4)Li3Cr3 octahedra, and edges with eight equivalent O(2)Li3Cr3 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the fifth O site, O(5) is bonded to one Li(5), one Li(6), two equivalent Li(1), and two equivalent Si(1) atoms to form OLi4Si2 octahedra that share corners with two equivalent O(5)Li4Si2 octahedra, corners with four equivalent O(3)Li3Cr2Si octahedra, edges with two equivalent O(3)Li3Cr2Si octahedra, edges with two equivalent O(5)Li4Si2 octahedra, and edges with eight equivalent O(1)Li4CrSi octahedra. The corner-sharing octahedral tilt angles range from 0-3°. is represented by the CIF card [CIF]
data_Li9Cr5(SiO8)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.549
_cell_length_b   5.051
_cell_length_c   5.069
_cell_angle_alpha   70.715
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   279.069
_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  0.383  0.000  0.000  1.0
  Li  Li1  1  0.124  0.000  0.000  1.0
  Li  Li2  1  0.257  0.500  0.000  1.0
  Li  Li3  1  0.876  0.000  0.000  1.0
  Li  Li4  1  0.000  0.500  0.000  1.0
  Li  Li5  1  0.617  0.000  0.000  1.0
  Li  Li6  1  0.743  0.500  0.000  1.0
  Li  Li7  1  0.500  0.000  0.500  1.0
  Li  Li8  1  0.500  0.500  0.000  1.0
  Cr  Cr9  1  0.259  0.000  0.500  1.0
  Cr  Cr10  1  0.000  0.000  0.500  1.0
  Cr  Cr11  1  0.130  0.500  0.500  1.0
  Cr  Cr12  1  0.741  0.000  0.500  1.0
  Cr  Cr13  1  0.870  0.500  0.500  1.0
  Si  Si14  1  0.383  0.500  0.500  1.0
  Si  Si15  1  0.617  0.500  0.500  1.0
  O  O16  1  0.375  0.722  0.712  1.0
  O  O17  1  0.128  0.759  0.728  1.0
  O  O18  1  0.265  0.730  0.281  1.0
  O  O19  1  0.000  0.739  0.272  1.0
  O  O20  1  0.265  0.270  0.719  1.0
  O  O21  1  0.872  0.759  0.728  1.0
  O  O22  1  0.375  0.278  0.288  1.0
  O  O23  1  0.000  0.261  0.728  1.0
  O  O24  1  0.625  0.722  0.712  1.0
  O  O25  1  0.735  0.730  0.281  1.0
  O  O26  1  0.128  0.241  0.272  1.0
  O  O27  1  0.872  0.241  0.272  1.0
  O  O28  1  0.735  0.270  0.719  1.0
  O  O29  1  0.500  0.707  0.286  1.0
  O  O30  1  0.625  0.278  0.288  1.0
  O  O31  1  0.500  0.293  0.714  1.0
[/CIF]
.