The structure described by Ca9(FeN4)2 crystallizes in the monoclinic C2/m space group. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a linear geometry to two equivalent N(4) atoms. In the second Ca site, Ca(2) is bonded to one N(2), two equivalent N(1), and two equivalent N(4) atoms to form a mixture of distorted corner and edge-sharing CaN5 square pyramids. In the third Ca site, Ca(3) is bonded to one N(3), one N(4), and three equivalent N(2) atoms to form a mixture of distorted corner and edge-sharing CaN5 trigonal bipyramids. In the fourth Ca site, Ca(4) is bonded in a 5-coordinate geometry to one N(3), two equivalent N(1), and two equivalent N(4) atoms. In the fifth Ca site, Ca(5) is bonded in a 5-coordinate geometry to one N(1), one N(2), and three equivalent N(3) atoms. Fe(1) is bonded in a trigonal planar geometry to one N(1), one N(2), and one N(3) atom. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Ca(5), two equivalent Ca(2), two equivalent Ca(4), and one Fe(1) atom to form distorted NCa5Fe octahedra that share corners with two equivalent N(1)Ca5Fe octahedra,  an edgeedge with one N(1)Ca5Fe octahedra, and edges with four equivalent N(4)Ca6 octahedra. The corner-sharing octahedral tilt angles are 17°. In the second N site, N(2) is bonded in a 5-coordinate geometry to one Ca(2), one Ca(5), three equivalent Ca(3), and one Fe(1) atom. In the third N site, N(3) is bonded in a 6-coordinate geometry to one Ca(3), one Ca(4), three equivalent Ca(5), and one Fe(1) atom. In the fourth N site, N(4) is bonded to one Ca(1), one Ca(3), two equivalent Ca(2), and two equivalent Ca(4) atoms to form NCa6 octahedra that share corners with three equivalent N(4)Ca6 octahedra,  an edgeedge with one N(4)Ca6 octahedra, and edges with four equivalent N(1)Ca5Fe octahedra. The corner-sharing octahedral tilt angles range from 0-5°. is represented by the CIF file [CIF]
data_Ca9(FeN4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.557
_cell_length_b   4.926
_cell_length_c   7.821
_cell_angle_alpha   90.000
_cell_angle_beta   69.406
_cell_angle_gamma   75.066
_symmetry_Int_Tables_number   1
_cell_volume   331.290
_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
  Ca  Ca0  1  0.000  0.500  0.500  1.0
  Ca  Ca1  1  0.076  0.962  0.766  1.0
  Ca  Ca2  1  0.924  0.038  0.234  1.0
  Ca  Ca3  1  0.654  0.673  0.449  1.0
  Ca  Ca4  1  0.346  0.327  0.551  1.0
  Ca  Ca5  1  0.824  0.588  0.984  1.0
  Ca  Ca6  1  0.176  0.412  0.016  1.0
  Ca  Ca7  1  0.612  0.194  0.819  1.0
  Ca  Ca8  1  0.388  0.806  0.181  1.0
  Fe  Fe9  1  0.387  0.806  0.801  1.0
  Fe  Fe10  1  0.613  0.194  0.199  1.0
  N  N11  1  0.218  0.891  0.999  1.0
  N  N12  1  0.782  0.109  0.001  1.0
  N  N13  1  0.364  0.818  0.591  1.0
  N  N14  1  0.636  0.182  0.409  1.0
  N  N15  1  0.573  0.713  0.811  1.0
  N  N16  1  0.427  0.287  0.189  1.0
  N  N17  1  0.073  0.464  0.753  1.0
  N  N18  1  0.927  0.536  0.247  1.0
[/CIF]
.
The structure described by Ca9(FeN4)2 crystallizes in the monoclinic C2/m space group. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a linear geometry to two equivalent N(4) atoms. In the second Ca site, Ca(2) is bonded to one N(2), two equivalent N(1), and two equivalent N(4) atoms to form a mixture of distorted corner and edge-sharing CaN5 square pyramids. In the third Ca site, Ca(3) is bonded to one N(3), one N(4), and three equivalent N(2) atoms to form a mixture of distorted corner and edge-sharing CaN5 trigonal bipyramids. In the fourth Ca site, Ca(4) is bonded in a 5-coordinate geometry to one N(3), two equivalent N(1), and two equivalent N(4) atoms. In the fifth Ca site, Ca(5) is bonded in a 5-coordinate geometry to one N(1), one N(2), and three equivalent N(3) atoms. Fe(1) is bonded in a trigonal planar geometry to one N(1), one N(2), and one N(3) atom. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Ca(5), two equivalent Ca(2), two equivalent Ca(4), and one Fe(1) atom to form distorted NCa5Fe octahedra that share corners with two equivalent N(1)Ca5Fe octahedra,  an edgeedge with one N(1)Ca5Fe octahedra, and edges with four equivalent N(4)Ca6 octahedra. The corner-sharing octahedral tilt angles are 17°. In the second N site, N(2) is bonded in a 5-coordinate geometry to one Ca(2), one Ca(5), three equivalent Ca(3), and one Fe(1) atom. In the third N site, N(3) is bonded in a 6-coordinate geometry to one Ca(3), one Ca(4), three equivalent Ca(5), and one Fe(1) atom. In the fourth N site, N(4) is bonded to one Ca(1), one Ca(3), two equivalent Ca(2), and two equivalent Ca(4) atoms to form NCa6 octahedra that share corners with three equivalent N(4)Ca6 octahedra,  an edgeedge with one N(4)Ca6 octahedra, and edges with four equivalent N(1)Ca5Fe octahedra. The corner-sharing octahedral tilt angles range from 0-5°. is represented by the CIF file [CIF]
data_Ca9(FeN4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.557
_cell_length_b   4.926
_cell_length_c   7.821
_cell_angle_alpha   90.000
_cell_angle_beta   69.406
_cell_angle_gamma   75.066
_symmetry_Int_Tables_number   1
_cell_volume   331.290
_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
  Ca  Ca0  1  0.000  0.500  0.500  1.0
  Ca  Ca1  1  0.076  0.962  0.766  1.0
  Ca  Ca2  1  0.924  0.038  0.234  1.0
  Ca  Ca3  1  0.654  0.673  0.449  1.0
  Ca  Ca4  1  0.346  0.327  0.551  1.0
  Ca  Ca5  1  0.824  0.588  0.984  1.0
  Ca  Ca6  1  0.176  0.412  0.016  1.0
  Ca  Ca7  1  0.612  0.194  0.819  1.0
  Ca  Ca8  1  0.388  0.806  0.181  1.0
  Fe  Fe9  1  0.387  0.806  0.801  1.0
  Fe  Fe10  1  0.613  0.194  0.199  1.0
  N  N11  1  0.218  0.891  0.999  1.0
  N  N12  1  0.782  0.109  0.001  1.0
  N  N13  1  0.364  0.818  0.591  1.0
  N  N14  1  0.636  0.182  0.409  1.0
  N  N15  1  0.573  0.713  0.811  1.0
  N  N16  1  0.427  0.287  0.189  1.0
  N  N17  1  0.073  0.464  0.753  1.0
  N  N18  1  0.927  0.536  0.247  1.0
[/CIF]
.