The material described by Na3FeCAsO7 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 to one O(1), one O(2), one O(3), one O(4), one O(5), and two equivalent O(6) atoms to form distorted NaO7 pentagonal bipyramids that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Na(2)O7 pentagonal bipyramids, corners with two equivalent As(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Na(2)O7 pentagonal bipyramid,  an edgeedge with one As(1)O4 tetrahedra,  a faceface with one Fe(1)O6 octahedra, and  a faceface with one Na(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 56°. Fe(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 FeO6 octahedra that share corners with two equivalent Na(2)O7 pentagonal bipyramids, corners with four equivalent As(1)O4 tetrahedra, edges with two equivalent Na(2)O7 pentagonal bipyramids, and faces with two equivalent Na(2)O7 pentagonal bipyramids. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. As(1) is bonded to one O(4), one O(5), and two equivalent O(6) atoms to form AsO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent Na(2)O7 pentagonal bipyramids, and edges with two equivalent Na(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-62°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-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 5-coordinate geometry to one Na(1), two equivalent Na(2), one Fe(1), and one C(1) atom. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), one Fe(1), and one C(1) atom to form distorted corner-sharing ONa3FeC trigonal bipyramids. In the fourth O site, O(4) is bonded to two equivalent Na(2), one Fe(1), and one As(1) atom to form distorted corner-sharing ONa2FeAs tetrahedra. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to two equivalent Na(2), one Fe(1), and one As(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 Fe(1), and one As(1) atom. is represented by the CIF file [CIF]
data_Na3FeAsCO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.148
_cell_length_b   6.679
_cell_length_c   9.137
_cell_angle_alpha   89.997
_cell_angle_beta   90.656
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   314.155
_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
  As  As0  1  0.693  0.250  0.586  1.0
  As  As1  1  0.307  0.750  0.415  1.0
  C  C2  1  0.722  0.750  0.946  1.0
  C  C3  1  0.278  0.250  0.054  1.0
  Fe  Fe4  1  0.780  0.750  0.656  1.0
  Fe  Fe5  1  0.220  0.250  0.344  1.0
  Na  Na6  1  0.769  0.250  0.919  1.0
  Na  Na7  1  0.231  0.750  0.081  1.0
  Na  Na8  1  0.248  0.998  0.745  1.0
  Na  Na9  1  0.248  0.502  0.745  1.0
  Na  Na10  1  0.752  0.498  0.255  1.0
  Na  Na11  1  0.752  0.002  0.255  1.0
  O  O12  1  0.289  0.250  0.913  1.0
  O  O13  1  0.711  0.750  0.087  1.0
  O  O14  1  0.945  0.750  0.882  1.0
  O  O15  1  0.055  0.250  0.118  1.0
  O  O16  1  0.512  0.750  0.867  1.0
  O  O17  1  0.488  0.250  0.133  1.0
  O  O18  1  0.364  0.250  0.560  1.0
  O  O19  1  0.636  0.750  0.440  1.0
  O  O20  1  0.160  0.750  0.579  1.0
  O  O21  1  0.840  0.250  0.421  1.0
  O  O22  1  0.774  0.051  0.694  1.0
  O  O23  1  0.774  0.450  0.694  1.0
  O  O24  1  0.226  0.550  0.306  1.0
  O  O25  1  0.226  0.949  0.306  1.0
[/CIF]
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The material described by Na3FeCAsO7 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 to one O(1), one O(2), one O(3), one O(4), one O(5), and two equivalent O(6) atoms to form distorted NaO7 pentagonal bipyramids that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Na(2)O7 pentagonal bipyramids, corners with two equivalent As(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Na(2)O7 pentagonal bipyramid,  an edgeedge with one As(1)O4 tetrahedra,  a faceface with one Fe(1)O6 octahedra, and  a faceface with one Na(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 56°. Fe(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 FeO6 octahedra that share corners with two equivalent Na(2)O7 pentagonal bipyramids, corners with four equivalent As(1)O4 tetrahedra, edges with two equivalent Na(2)O7 pentagonal bipyramids, and faces with two equivalent Na(2)O7 pentagonal bipyramids. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. As(1) is bonded to one O(4), one O(5), and two equivalent O(6) atoms to form AsO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent Na(2)O7 pentagonal bipyramids, and edges with two equivalent Na(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-62°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-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 5-coordinate geometry to one Na(1), two equivalent Na(2), one Fe(1), and one C(1) atom. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), one Fe(1), and one C(1) atom to form distorted corner-sharing ONa3FeC trigonal bipyramids. In the fourth O site, O(4) is bonded to two equivalent Na(2), one Fe(1), and one As(1) atom to form distorted corner-sharing ONa2FeAs tetrahedra. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to two equivalent Na(2), one Fe(1), and one As(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 Fe(1), and one As(1) atom. is represented by the CIF file [CIF]
data_Na3FeAsCO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.148
_cell_length_b   6.679
_cell_length_c   9.137
_cell_angle_alpha   89.997
_cell_angle_beta   90.656
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   314.155
_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
  As  As0  1  0.693  0.250  0.586  1.0
  As  As1  1  0.307  0.750  0.415  1.0
  C  C2  1  0.722  0.750  0.946  1.0
  C  C3  1  0.278  0.250  0.054  1.0
  Fe  Fe4  1  0.780  0.750  0.656  1.0
  Fe  Fe5  1  0.220  0.250  0.344  1.0
  Na  Na6  1  0.769  0.250  0.919  1.0
  Na  Na7  1  0.231  0.750  0.081  1.0
  Na  Na8  1  0.248  0.998  0.745  1.0
  Na  Na9  1  0.248  0.502  0.745  1.0
  Na  Na10  1  0.752  0.498  0.255  1.0
  Na  Na11  1  0.752  0.002  0.255  1.0
  O  O12  1  0.289  0.250  0.913  1.0
  O  O13  1  0.711  0.750  0.087  1.0
  O  O14  1  0.945  0.750  0.882  1.0
  O  O15  1  0.055  0.250  0.118  1.0
  O  O16  1  0.512  0.750  0.867  1.0
  O  O17  1  0.488  0.250  0.133  1.0
  O  O18  1  0.364  0.250  0.560  1.0
  O  O19  1  0.636  0.750  0.440  1.0
  O  O20  1  0.160  0.750  0.579  1.0
  O  O21  1  0.840  0.250  0.421  1.0
  O  O22  1  0.774  0.051  0.694  1.0
  O  O23  1  0.774  0.450  0.694  1.0
  O  O24  1  0.226  0.550  0.306  1.0
  O  O25  1  0.226  0.949  0.306  1.0
[/CIF]
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