The compound described by FeAl4(SiO6)2 crystallizes in the orthorhombic Cmcm space group. Fe(1) is bonded to two equivalent O(1) and two equivalent O(5) atoms to form FeO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra and corners with six equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-61°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, edges with two equivalent Al(1)O6 octahedra, and edges with two equivalent Al(2)O6 octahedra. In the second Al site, Al(2) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form AlO6 octahedra that share corners with three equivalent Fe(1)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra,  an edgeedge with one Al(2)O6 octahedra, and edges with two equivalent Al(1)O6 octahedra. Si(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with three equivalent Al(2)O6 octahedra and corners with four equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-54°. There are five inequivalent O sites. In the first O site, O(2) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one Si(1) atom. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(1) atom. In the third O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Al(1) and one Si(1) atom. In the fourth O site, O(5) is bonded to one Fe(1), one Al(2), and two equivalent Al(1) atoms to form distorted corner-sharing OAl3Fe trigonal pyramids. In the fifth O site, O(1) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Al(2) atoms. is represented by the CIF card [CIF]
data_Al4Fe(SiO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.641
_cell_length_b   7.874
_cell_length_c   9.373
_cell_angle_alpha   114.836
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   377.783
_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
  Al  Al0  1  0.500  0.673  0.346  1.0
  Al  Al1  1  0.000  0.673  0.346  1.0
  Al  Al2  1  0.500  0.327  0.654  1.0
  Al  Al3  1  0.000  0.327  0.654  1.0
  Al  Al4  1  0.250  0.856  0.172  1.0
  Al  Al5  1  0.750  0.316  0.172  1.0
  Al  Al6  1  0.750  0.144  0.828  1.0
  Al  Al7  1  0.250  0.684  0.828  1.0
  Fe  Fe8  1  0.250  0.376  0.000  1.0
  Fe  Fe9  1  0.750  0.624  0.000  1.0
  Si  Si10  1  0.250  0.966  0.662  1.0
  Si  Si11  1  0.750  0.696  0.662  1.0
  Si  Si12  1  0.750  0.034  0.338  1.0
  Si  Si13  1  0.250  0.304  0.338  1.0
  O  O14  1  0.535  0.255  0.000  1.0
  O  O15  1  0.465  0.745  0.000  1.0
  O  O16  1  0.965  0.255  0.000  1.0
  O  O17  1  0.035  0.745  0.000  1.0
  O  O18  1  0.486  0.097  0.678  1.0
  O  O19  1  0.514  0.581  0.678  1.0
  O  O20  1  0.014  0.097  0.678  1.0
  O  O21  1  0.986  0.581  0.678  1.0
  O  O22  1  0.514  0.903  0.322  1.0
  O  O23  1  0.486  0.419  0.322  1.0
  O  O24  1  0.986  0.903  0.322  1.0
  O  O25  1  0.014  0.419  0.322  1.0
  O  O26  1  0.250  0.903  0.806  1.0
  O  O27  1  0.750  0.903  0.806  1.0
  O  O28  1  0.750  0.097  0.194  1.0
  O  O29  1  0.250  0.097  0.194  1.0
  O  O30  1  0.250  0.774  0.493  1.0
  O  O31  1  0.750  0.719  0.493  1.0
  O  O32  1  0.750  0.226  0.507  1.0
  O  O33  1  0.250  0.281  0.507  1.0
  O  O34  1  0.250  0.616  0.193  1.0
  O  O35  1  0.750  0.577  0.193  1.0
  O  O36  1  0.750  0.384  0.807  1.0
  O  O37  1  0.250  0.423  0.807  1.0
[/CIF]
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The compound described by FeAl4(SiO6)2 crystallizes in the orthorhombic Cmcm space group. Fe(1) is bonded to two equivalent O(1) and two equivalent O(5) atoms to form FeO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra and corners with six equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-61°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, edges with two equivalent Al(1)O6 octahedra, and edges with two equivalent Al(2)O6 octahedra. In the second Al site, Al(2) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form AlO6 octahedra that share corners with three equivalent Fe(1)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra,  an edgeedge with one Al(2)O6 octahedra, and edges with two equivalent Al(1)O6 octahedra. Si(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with three equivalent Al(2)O6 octahedra and corners with four equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-54°. There are five inequivalent O sites. In the first O site, O(2) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one Si(1) atom. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(1) atom. In the third O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Al(1) and one Si(1) atom. In the fourth O site, O(5) is bonded to one Fe(1), one Al(2), and two equivalent Al(1) atoms to form distorted corner-sharing OAl3Fe trigonal pyramids. In the fifth O site, O(1) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Al(2) atoms. is represented by the CIF card [CIF]
data_Al4Fe(SiO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.641
_cell_length_b   7.874
_cell_length_c   9.373
_cell_angle_alpha   114.836
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   377.783
_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
  Al  Al0  1  0.500  0.673  0.346  1.0
  Al  Al1  1  0.000  0.673  0.346  1.0
  Al  Al2  1  0.500  0.327  0.654  1.0
  Al  Al3  1  0.000  0.327  0.654  1.0
  Al  Al4  1  0.250  0.856  0.172  1.0
  Al  Al5  1  0.750  0.316  0.172  1.0
  Al  Al6  1  0.750  0.144  0.828  1.0
  Al  Al7  1  0.250  0.684  0.828  1.0
  Fe  Fe8  1  0.250  0.376  0.000  1.0
  Fe  Fe9  1  0.750  0.624  0.000  1.0
  Si  Si10  1  0.250  0.966  0.662  1.0
  Si  Si11  1  0.750  0.696  0.662  1.0
  Si  Si12  1  0.750  0.034  0.338  1.0
  Si  Si13  1  0.250  0.304  0.338  1.0
  O  O14  1  0.535  0.255  0.000  1.0
  O  O15  1  0.465  0.745  0.000  1.0
  O  O16  1  0.965  0.255  0.000  1.0
  O  O17  1  0.035  0.745  0.000  1.0
  O  O18  1  0.486  0.097  0.678  1.0
  O  O19  1  0.514  0.581  0.678  1.0
  O  O20  1  0.014  0.097  0.678  1.0
  O  O21  1  0.986  0.581  0.678  1.0
  O  O22  1  0.514  0.903  0.322  1.0
  O  O23  1  0.486  0.419  0.322  1.0
  O  O24  1  0.986  0.903  0.322  1.0
  O  O25  1  0.014  0.419  0.322  1.0
  O  O26  1  0.250  0.903  0.806  1.0
  O  O27  1  0.750  0.903  0.806  1.0
  O  O28  1  0.750  0.097  0.194  1.0
  O  O29  1  0.250  0.097  0.194  1.0
  O  O30  1  0.250  0.774  0.493  1.0
  O  O31  1  0.750  0.719  0.493  1.0
  O  O32  1  0.750  0.226  0.507  1.0
  O  O33  1  0.250  0.281  0.507  1.0
  O  O34  1  0.250  0.616  0.193  1.0
  O  O35  1  0.750  0.577  0.193  1.0
  O  O36  1  0.750  0.384  0.807  1.0
  O  O37  1  0.250  0.423  0.807  1.0
[/CIF]
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