The crystal structure described by Li2Cr(Si2O5)3 crystallizes in the triclinic P-1 space group. Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(7), and two equivalent O(3) atoms. Cr(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(7) atoms to form CrO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. In the third Si site, Si(3) is bonded to one O(4), one O(5), one O(7), and one O(8) atom to form SiO4 tetrahedra 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, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(1) and one Si(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded to two equivalent Li(1), one Cr(1), and one Si(2) atom to form a mixture of distorted edge and corner-sharing OLi2CrSi trigonal pyramids. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(1), one Cr(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a linear geometry to two equivalent Si(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2Cr(Si2O5)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.703
_cell_length_b   7.336
_cell_length_c   7.339
_cell_angle_alpha   97.513
_cell_angle_beta   114.085
_cell_angle_gamma   110.973
_symmetry_Int_Tables_number   1
_cell_volume   290.943
_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  0.296  0.829  0.809  1.0
  Li  Li1  1  0.704  0.171  0.191  1.0
  Cr  Cr2  1  0.000  0.000  0.000  1.0
  Si  Si3  1  0.131  0.393  0.828  1.0
  Si  Si4  1  0.647  0.213  0.798  1.0
  Si  Si5  1  0.276  0.304  0.487  1.0
  Si  Si6  1  0.724  0.696  0.513  1.0
  Si  Si7  1  0.353  0.787  0.202  1.0
  Si  Si8  1  0.869  0.607  0.172  1.0
  O  O9  1  0.176  0.231  0.947  1.0
  O  O10  1  0.690  0.365  0.014  1.0
  O  O11  1  0.661  0.011  0.855  1.0
  O  O12  1  0.175  0.394  0.627  1.0
  O  O13  1  0.377  0.151  0.601  1.0
  O  O14  1  0.846  0.349  0.735  1.0
  O  O15  1  0.954  0.824  0.749  1.0
  O  O16  1  0.500  0.500  0.500  1.0
  O  O17  1  0.046  0.176  0.251  1.0
  O  O18  1  0.154  0.651  0.265  1.0
  O  O19  1  0.623  0.849  0.399  1.0
  O  O20  1  0.825  0.606  0.373  1.0
  O  O21  1  0.339  0.989  0.145  1.0
  O  O22  1  0.310  0.635  0.986  1.0
  O  O23  1  0.824  0.769  0.053  1.0
[/CIF]
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The crystal structure described by Li2Cr(Si2O5)3 crystallizes in the triclinic P-1 space group. Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(7), and two equivalent O(3) atoms. Cr(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(7) atoms to form CrO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. In the third Si site, Si(3) is bonded to one O(4), one O(5), one O(7), and one O(8) atom to form SiO4 tetrahedra 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, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(1) and one Si(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded to two equivalent Li(1), one Cr(1), and one Si(2) atom to form a mixture of distorted edge and corner-sharing OLi2CrSi trigonal pyramids. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(1), one Cr(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a linear geometry to two equivalent Si(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2Cr(Si2O5)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.703
_cell_length_b   7.336
_cell_length_c   7.339
_cell_angle_alpha   97.513
_cell_angle_beta   114.085
_cell_angle_gamma   110.973
_symmetry_Int_Tables_number   1
_cell_volume   290.943
_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  0.296  0.829  0.809  1.0
  Li  Li1  1  0.704  0.171  0.191  1.0
  Cr  Cr2  1  0.000  0.000  0.000  1.0
  Si  Si3  1  0.131  0.393  0.828  1.0
  Si  Si4  1  0.647  0.213  0.798  1.0
  Si  Si5  1  0.276  0.304  0.487  1.0
  Si  Si6  1  0.724  0.696  0.513  1.0
  Si  Si7  1  0.353  0.787  0.202  1.0
  Si  Si8  1  0.869  0.607  0.172  1.0
  O  O9  1  0.176  0.231  0.947  1.0
  O  O10  1  0.690  0.365  0.014  1.0
  O  O11  1  0.661  0.011  0.855  1.0
  O  O12  1  0.175  0.394  0.627  1.0
  O  O13  1  0.377  0.151  0.601  1.0
  O  O14  1  0.846  0.349  0.735  1.0
  O  O15  1  0.954  0.824  0.749  1.0
  O  O16  1  0.500  0.500  0.500  1.0
  O  O17  1  0.046  0.176  0.251  1.0
  O  O18  1  0.154  0.651  0.265  1.0
  O  O19  1  0.623  0.849  0.399  1.0
  O  O20  1  0.825  0.606  0.373  1.0
  O  O21  1  0.339  0.989  0.145  1.0
  O  O22  1  0.310  0.635  0.986  1.0
  O  O23  1  0.824  0.769  0.053  1.0
[/CIF]
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