The crystal structure described by CaFe2As2 crystallizes in the tetragonal I4/mmm space group. Ca(1) is bonded in a distorted body-centered cubic geometry to eight equivalent As(1) atoms. Fe(1) is bonded to four equivalent As(1) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. As(1) is bonded in a 8-coordinate geometry to four equivalent Ca(1) and four equivalent Fe(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca(FeAs)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.883
_cell_length_b   3.883
_cell_length_c   6.508
_cell_angle_alpha   107.348
_cell_angle_beta   107.318
_cell_angle_gamma   90.075
_symmetry_Int_Tables_number   1
_cell_volume   88.983
_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
  As  As0  1  0.376  0.376  0.752  1.0
  As  As1  1  0.624  0.624  0.248  1.0
  Ca  Ca2  1  1.000  1.000  0.000  1.0
  Fe  Fe3  1  0.750  0.250  0.500  1.0
  Fe  Fe4  1  0.250  0.750  0.500  1.0
[/CIF]
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The crystal structure described by CaFe2As2 crystallizes in the tetragonal I4/mmm space group. Ca(1) is bonded in a distorted body-centered cubic geometry to eight equivalent As(1) atoms. Fe(1) is bonded to four equivalent As(1) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. As(1) is bonded in a 8-coordinate geometry to four equivalent Ca(1) and four equivalent Fe(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca(FeAs)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.883
_cell_length_b   3.883
_cell_length_c   6.508
_cell_angle_alpha   107.348
_cell_angle_beta   107.318
_cell_angle_gamma   90.075
_symmetry_Int_Tables_number   1
_cell_volume   88.983
_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
  As  As0  1  0.376  0.376  0.752  1.0
  As  As1  1  0.624  0.624  0.248  1.0
  Ca  Ca2  1  1.000  1.000  0.000  1.0
  Fe  Fe3  1  0.750  0.250  0.500  1.0
  Fe  Fe4  1  0.250  0.750  0.500  1.0
[/CIF]
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