The compound described by Fe4As2O11 crystallizes in the triclinic P-1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(1) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with three equivalent As(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-32°. In the second Fe site, Fe(2) is bonded to one O(3), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with four equivalent As(1)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 32°. As(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form AsO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra and corners with four equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-57°. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Fe(1) and two equivalent Fe(2) atoms to form distorted edge-sharing OFe4 tetrahedra. In the second O site, O(2) is bonded in a linear geometry to two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one As(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Fe(2) and one As(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one As(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one As(1) atom. is represented by the CIF card [CIF]
data_Fe4As2O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.144
_cell_length_b   6.575
_cell_length_c   6.733
_cell_angle_alpha   108.941
_cell_angle_beta   106.129
_cell_angle_gamma   98.148
_symmetry_Int_Tables_number   1
_cell_volume   200.079
_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
  Fe  Fe0  1  0.104  0.753  0.032  1.0
  Fe  Fe1  1  0.896  0.247  0.968  1.0
  Fe  Fe2  1  0.658  0.628  0.251  1.0
  Fe  Fe3  1  0.342  0.372  0.749  1.0
  As  As4  1  0.337  0.815  0.606  1.0
  As  As5  1  0.663  0.185  0.394  1.0
  O  O6  1  0.739  0.525  0.956  1.0
  O  O7  1  0.261  0.475  0.044  1.0
  O  O8  1  0.000  0.000  0.000  1.0
  O  O9  1  0.926  0.207  0.632  1.0
  O  O10  1  0.074  0.793  0.368  1.0
  O  O11  1  0.393  0.278  0.461  1.0
  O  O12  1  0.215  0.656  0.738  1.0
  O  O13  1  0.784  0.344  0.262  1.0
  O  O14  1  0.463  0.091  0.788  1.0
  O  O15  1  0.537  0.909  0.212  1.0
  O  O16  1  0.607  0.722  0.539  1.0
[/CIF]
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The compound described by Fe4As2O11 crystallizes in the triclinic P-1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(1) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with three equivalent As(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-32°. In the second Fe site, Fe(2) is bonded to one O(3), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with four equivalent As(1)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 32°. As(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form AsO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra and corners with four equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-57°. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Fe(1) and two equivalent Fe(2) atoms to form distorted edge-sharing OFe4 tetrahedra. In the second O site, O(2) is bonded in a linear geometry to two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one As(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Fe(2) and one As(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one As(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one As(1) atom. is represented by the CIF card [CIF]
data_Fe4As2O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.144
_cell_length_b   6.575
_cell_length_c   6.733
_cell_angle_alpha   108.941
_cell_angle_beta   106.129
_cell_angle_gamma   98.148
_symmetry_Int_Tables_number   1
_cell_volume   200.079
_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
  Fe  Fe0  1  0.104  0.753  0.032  1.0
  Fe  Fe1  1  0.896  0.247  0.968  1.0
  Fe  Fe2  1  0.658  0.628  0.251  1.0
  Fe  Fe3  1  0.342  0.372  0.749  1.0
  As  As4  1  0.337  0.815  0.606  1.0
  As  As5  1  0.663  0.185  0.394  1.0
  O  O6  1  0.739  0.525  0.956  1.0
  O  O7  1  0.261  0.475  0.044  1.0
  O  O8  1  0.000  0.000  0.000  1.0
  O  O9  1  0.926  0.207  0.632  1.0
  O  O10  1  0.074  0.793  0.368  1.0
  O  O11  1  0.393  0.278  0.461  1.0
  O  O12  1  0.215  0.656  0.738  1.0
  O  O13  1  0.784  0.344  0.262  1.0
  O  O14  1  0.463  0.091  0.788  1.0
  O  O15  1  0.537  0.909  0.212  1.0
  O  O16  1  0.607  0.722  0.539  1.0
[/CIF]
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