The material structure described by CaCo4O9 crystallizes in the tetragonal P4/n space group. Ca(1) is bonded in a 8-coordinate geometry to four equivalent O(2) and four equivalent O(3) atoms. Co(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), and three equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted square co-planar geometry to four equivalent Co(1) atoms. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one Co(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1) and three equivalent Co(1) atoms. is represented by the CIF file [CIF]
data_CaCo4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.269
_cell_length_b   8.269
_cell_length_c   5.195
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   355.205
_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
  Ca  Ca0  1  0.000  0.500  0.862  1.0
  Ca  Ca1  1  0.500  0.000  0.138  1.0
  Co  Co2  1  0.714  0.412  0.392  1.0
  Co  Co3  1  0.412  0.286  0.608  1.0
  Co  Co4  1  0.912  0.786  0.392  1.0
  Co  Co5  1  0.214  0.912  0.608  1.0
  Co  Co6  1  0.286  0.588  0.392  1.0
  Co  Co7  1  0.088  0.214  0.392  1.0
  Co  Co8  1  0.786  0.088  0.608  1.0
  Co  Co9  1  0.588  0.714  0.608  1.0
  O  O10  1  0.500  0.500  0.500  1.0
  O  O11  1  0.000  0.000  0.500  1.0
  O  O12  1  0.572  0.756  0.918  1.0
  O  O13  1  0.744  0.072  0.918  1.0
  O  O14  1  0.256  0.928  0.918  1.0
  O  O15  1  0.428  0.244  0.918  1.0
  O  O16  1  0.928  0.744  0.082  1.0
  O  O17  1  0.756  0.428  0.082  1.0
  O  O18  1  0.244  0.572  0.082  1.0
  O  O19  1  0.072  0.256  0.082  1.0
  O  O20  1  0.210  0.394  0.552  1.0
  O  O21  1  0.106  0.710  0.552  1.0
  O  O22  1  0.894  0.290  0.552  1.0
  O  O23  1  0.790  0.606  0.552  1.0
  O  O24  1  0.710  0.894  0.448  1.0
  O  O25  1  0.394  0.790  0.448  1.0
  O  O26  1  0.606  0.210  0.448  1.0
  O  O27  1  0.290  0.106  0.448  1.0
[/CIF]
.
The material structure described by CaCo4O9 crystallizes in the tetragonal P4/n space group. Ca(1) is bonded in a 8-coordinate geometry to four equivalent O(2) and four equivalent O(3) atoms. Co(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), and three equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted square co-planar geometry to four equivalent Co(1) atoms. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one Co(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1) and three equivalent Co(1) atoms. is represented by the CIF file [CIF]
data_CaCo4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.269
_cell_length_b   8.269
_cell_length_c   5.195
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   355.205
_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
  Ca  Ca0  1  0.000  0.500  0.862  1.0
  Ca  Ca1  1  0.500  0.000  0.138  1.0
  Co  Co2  1  0.714  0.412  0.392  1.0
  Co  Co3  1  0.412  0.286  0.608  1.0
  Co  Co4  1  0.912  0.786  0.392  1.0
  Co  Co5  1  0.214  0.912  0.608  1.0
  Co  Co6  1  0.286  0.588  0.392  1.0
  Co  Co7  1  0.088  0.214  0.392  1.0
  Co  Co8  1  0.786  0.088  0.608  1.0
  Co  Co9  1  0.588  0.714  0.608  1.0
  O  O10  1  0.500  0.500  0.500  1.0
  O  O11  1  0.000  0.000  0.500  1.0
  O  O12  1  0.572  0.756  0.918  1.0
  O  O13  1  0.744  0.072  0.918  1.0
  O  O14  1  0.256  0.928  0.918  1.0
  O  O15  1  0.428  0.244  0.918  1.0
  O  O16  1  0.928  0.744  0.082  1.0
  O  O17  1  0.756  0.428  0.082  1.0
  O  O18  1  0.244  0.572  0.082  1.0
  O  O19  1  0.072  0.256  0.082  1.0
  O  O20  1  0.210  0.394  0.552  1.0
  O  O21  1  0.106  0.710  0.552  1.0
  O  O22  1  0.894  0.290  0.552  1.0
  O  O23  1  0.790  0.606  0.552  1.0
  O  O24  1  0.710  0.894  0.448  1.0
  O  O25  1  0.394  0.790  0.448  1.0
  O  O26  1  0.606  0.210  0.448  1.0
  O  O27  1  0.290  0.106  0.448  1.0
[/CIF]
.