The structure described by Na2FeSiCO7 crystallizes in the monoclinic P2_1/m space group. Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. Fe(1) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form distorted FeO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(5), one O(6), and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-50°. 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 3-coordinate geometry to two equivalent Na(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted trigonal pyramidal geometry to two equivalent Na(1), one Fe(1), and one C(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Fe(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to two equivalent Na(1), one Fe(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Fe(1), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2FeSiCO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.511
_cell_length_b   5.293
_cell_length_c   9.211
_cell_angle_alpha   89.306
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   317.454
_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
  Na  Na0  1  0.506  0.764  0.763  1.0
  Na  Na1  1  0.994  0.764  0.763  1.0
  Na  Na2  1  0.494  0.236  0.237  1.0
  Na  Na3  1  0.006  0.236  0.237  1.0
  Fe  Fe4  1  0.250  0.209  0.639  1.0
  Fe  Fe5  1  0.750  0.791  0.361  1.0
  Si  Si6  1  0.750  0.293  0.569  1.0
  Si  Si7  1  0.250  0.707  0.431  1.0
  C  C8  1  0.250  0.275  0.923  1.0
  C  C9  1  0.750  0.725  0.077  1.0
  O  O10  1  0.750  0.715  0.940  1.0
  O  O11  1  0.250  0.059  0.856  1.0
  O  O12  1  0.250  0.472  0.838  1.0
  O  O13  1  0.952  0.220  0.668  1.0
  O  O14  1  0.548  0.220  0.668  1.0
  O  O15  1  0.250  0.853  0.586  1.0
  O  O16  1  0.750  0.604  0.538  1.0
  O  O17  1  0.250  0.396  0.462  1.0
  O  O18  1  0.750  0.147  0.414  1.0
  O  O19  1  0.452  0.780  0.332  1.0
  O  O20  1  0.048  0.780  0.332  1.0
  O  O21  1  0.750  0.528  0.162  1.0
  O  O22  1  0.750  0.941  0.144  1.0
  O  O23  1  0.250  0.285  0.060  1.0
[/CIF]
.
The structure described by Na2FeSiCO7 crystallizes in the monoclinic P2_1/m space group. Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. Fe(1) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form distorted FeO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(5), one O(6), and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-50°. 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 3-coordinate geometry to two equivalent Na(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted trigonal pyramidal geometry to two equivalent Na(1), one Fe(1), and one C(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Fe(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to two equivalent Na(1), one Fe(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Fe(1), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2FeSiCO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.511
_cell_length_b   5.293
_cell_length_c   9.211
_cell_angle_alpha   89.306
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   317.454
_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
  Na  Na0  1  0.506  0.764  0.763  1.0
  Na  Na1  1  0.994  0.764  0.763  1.0
  Na  Na2  1  0.494  0.236  0.237  1.0
  Na  Na3  1  0.006  0.236  0.237  1.0
  Fe  Fe4  1  0.250  0.209  0.639  1.0
  Fe  Fe5  1  0.750  0.791  0.361  1.0
  Si  Si6  1  0.750  0.293  0.569  1.0
  Si  Si7  1  0.250  0.707  0.431  1.0
  C  C8  1  0.250  0.275  0.923  1.0
  C  C9  1  0.750  0.725  0.077  1.0
  O  O10  1  0.750  0.715  0.940  1.0
  O  O11  1  0.250  0.059  0.856  1.0
  O  O12  1  0.250  0.472  0.838  1.0
  O  O13  1  0.952  0.220  0.668  1.0
  O  O14  1  0.548  0.220  0.668  1.0
  O  O15  1  0.250  0.853  0.586  1.0
  O  O16  1  0.750  0.604  0.538  1.0
  O  O17  1  0.250  0.396  0.462  1.0
  O  O18  1  0.750  0.147  0.414  1.0
  O  O19  1  0.452  0.780  0.332  1.0
  O  O20  1  0.048  0.780  0.332  1.0
  O  O21  1  0.750  0.528  0.162  1.0
  O  O22  1  0.750  0.941  0.144  1.0
  O  O23  1  0.250  0.285  0.060  1.0
[/CIF]
.