The material described by Na3CrSiCO7 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), two equivalent O(1), and two equivalent O(6) atoms. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and two equivalent O(6) atoms. Cr(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(6) atoms to form distorted CrO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(4), one O(5), and two equivalent O(6) atoms to form SiO4 tetrahedra that share corners with four equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-47°. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Na(1), two equivalent Na(2), and one C(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), two equivalent Na(2), one Cr(1), and one C(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Cr(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Na(2), one Cr(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted tetrahedral geometry to two equivalent Na(2), one Cr(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Cr(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Na3CrSiCO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.268
_cell_length_b   6.647
_cell_length_c   8.918
_cell_angle_alpha   90.002
_cell_angle_beta   92.186
_cell_angle_gamma   90.001
_symmetry_Int_Tables_number   1
_cell_volume   312.036
_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
  C  C0  1  0.715  0.750  0.939  1.0
  C  C1  1  0.285  0.250  0.061  1.0
  Cr  Cr2  1  0.786  0.750  0.660  1.0
  Cr  Cr3  1  0.214  0.250  0.340  1.0
  Na  Na4  1  0.774  0.250  0.911  1.0
  Na  Na5  1  0.226  0.750  0.089  1.0
  Na  Na6  1  0.261  0.017  0.720  1.0
  Na  Na7  1  0.261  0.483  0.720  1.0
  Na  Na8  1  0.739  0.517  0.280  1.0
  Na  Na9  1  0.739  0.983  0.280  1.0
  O  O10  1  0.316  0.250  0.920  1.0
  O  O11  1  0.684  0.750  0.080  1.0
  O  O12  1  0.941  0.750  0.883  1.0
  O  O13  1  0.059  0.250  0.117  1.0
  O  O14  1  0.523  0.750  0.841  1.0
  O  O15  1  0.477  0.250  0.159  1.0
  O  O16  1  0.410  0.250  0.535  1.0
  O  O17  1  0.590  0.750  0.465  1.0
  O  O18  1  0.126  0.750  0.577  1.0
  O  O19  1  0.874  0.250  0.423  1.0
  O  O20  1  0.786  0.053  0.686  1.0
  O  O21  1  0.786  0.447  0.686  1.0
  O  O22  1  0.214  0.553  0.314  1.0
  O  O23  1  0.214  0.947  0.314  1.0
  Si  Si24  1  0.718  0.250  0.578  1.0
  Si  Si25  1  0.282  0.750  0.422  1.0
[/CIF]
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The material described by Na3CrSiCO7 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), two equivalent O(1), and two equivalent O(6) atoms. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and two equivalent O(6) atoms. Cr(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(6) atoms to form distorted CrO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(4), one O(5), and two equivalent O(6) atoms to form SiO4 tetrahedra that share corners with four equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-47°. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Na(1), two equivalent Na(2), and one C(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), two equivalent Na(2), one Cr(1), and one C(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Cr(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Na(2), one Cr(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted tetrahedral geometry to two equivalent Na(2), one Cr(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Cr(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Na3CrSiCO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.268
_cell_length_b   6.647
_cell_length_c   8.918
_cell_angle_alpha   90.002
_cell_angle_beta   92.186
_cell_angle_gamma   90.001
_symmetry_Int_Tables_number   1
_cell_volume   312.036
_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
  C  C0  1  0.715  0.750  0.939  1.0
  C  C1  1  0.285  0.250  0.061  1.0
  Cr  Cr2  1  0.786  0.750  0.660  1.0
  Cr  Cr3  1  0.214  0.250  0.340  1.0
  Na  Na4  1  0.774  0.250  0.911  1.0
  Na  Na5  1  0.226  0.750  0.089  1.0
  Na  Na6  1  0.261  0.017  0.720  1.0
  Na  Na7  1  0.261  0.483  0.720  1.0
  Na  Na8  1  0.739  0.517  0.280  1.0
  Na  Na9  1  0.739  0.983  0.280  1.0
  O  O10  1  0.316  0.250  0.920  1.0
  O  O11  1  0.684  0.750  0.080  1.0
  O  O12  1  0.941  0.750  0.883  1.0
  O  O13  1  0.059  0.250  0.117  1.0
  O  O14  1  0.523  0.750  0.841  1.0
  O  O15  1  0.477  0.250  0.159  1.0
  O  O16  1  0.410  0.250  0.535  1.0
  O  O17  1  0.590  0.750  0.465  1.0
  O  O18  1  0.126  0.750  0.577  1.0
  O  O19  1  0.874  0.250  0.423  1.0
  O  O20  1  0.786  0.053  0.686  1.0
  O  O21  1  0.786  0.447  0.686  1.0
  O  O22  1  0.214  0.553  0.314  1.0
  O  O23  1  0.214  0.947  0.314  1.0
  Si  Si24  1  0.718  0.250  0.578  1.0
  Si  Si25  1  0.282  0.750  0.422  1.0
[/CIF]
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