The material structure described by Ba3UHoFeO9 crystallizes in the trigonal P3m1 space group. There are six inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a distorted q6 geometry to three equivalent O(5) and six equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded to three equivalent O(2), three equivalent O(3), and six equivalent O(4) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(2)O12 cuboctahedra,  a faceface with one Fe(1)O6 octahedra, faces with three equivalent U(2)O6 octahedra, and faces with three equivalent Fe(2)O6 octahedra. In the third Ba site, Ba(3) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. In the fourth Ba site, Ba(4) is bonded in a distorted q6 geometry to three equivalent O(4) and six equivalent O(2) atoms. In the fifth Ba site, Ba(5) is bonded in a distorted hexagonal planar geometry to three equivalent O(5) and three equivalent O(6) atoms. In the sixth Ba site, Ba(6) is bonded in a distorted q6 geometry to three equivalent O(1) and six equivalent O(5) atoms. There are two inequivalent U sites. In the first U site, U(1) is bonded in an octahedral geometry to three equivalent O(1) and three equivalent O(5) atoms. In the second U site, U(2) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form UO6 octahedra that share corners with three equivalent Fe(2)O6 octahedra and faces with three equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 3-coordinate geometry to three equivalent O(3) and six equivalent O(6) atoms. In the second Ho site, Ho(2) is bonded in a 3-coordinate geometry to three equivalent O(6) and six equivalent O(3) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form FeO6 octahedra that share corners with three equivalent Fe(2)O6 octahedra and  a faceface with one Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 6°. In the second Fe site, Fe(2) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form FeO6 octahedra that share corners with three equivalent U(2)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and faces with three equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-6°. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Ba(3), one Ba(6), two equivalent Ba(1), and one U(1) atom to form a mixture of distorted edge, face, and corner-sharing OBa4U square pyramids. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(4), and one U(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Ba(2), one Ho(1), two equivalent Ho(2), one Fe(1), and one Fe(2) atom. In the fourth O site, O(4) is bonded to one Ba(4), two equivalent Ba(2), one U(2), and one Fe(2) atom to form a mixture of distorted edge, face, and corner-sharing OBa3UFe square pyramids. In the fifth O site, O(5) is bonded to one Ba(1), one Ba(5), two equivalent Ba(6), and one U(1) atom to form a mixture of distorted edge, face, and corner-sharing OBa4U square pyramids. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ba(5), one Ho(2), two equivalent Ho(1), and one Fe(1) atom. is represented by the CIF file [CIF]
data_Ba3HoUFeO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.994
_cell_length_b   5.994
_cell_length_c   17.327
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   539.060
_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
  Ba  Ba0  1  0.667  0.333  0.052  1.0
  Ba  Ba1  1  0.333  0.667  0.446  1.0
  Ba  Ba2  1  0.333  0.667  0.182  1.0
  Ba  Ba3  1  0.000  0.000  0.304  1.0
  Ba  Ba4  1  0.667  0.333  0.815  1.0
  Ba  Ba5  1  0.333  0.667  0.945  1.0
  Ho  Ho6  1  0.000  0.000  0.658  1.0
  Ho  Ho7  1  0.667  0.333  0.615  1.0
  U  U8  1  0.000  0.000  0.999  1.0
  U  U9  1  0.667  0.333  0.362  1.0
  Fe  Fe10  1  0.333  0.667  0.646  1.0
  Fe  Fe11  1  0.000  0.000  0.497  1.0
  O  O12  1  0.165  0.835  0.068  1.0
  O  O13  1  0.990  0.495  0.295  1.0
  O  O14  1  0.505  0.010  0.295  1.0
  O  O15  1  0.165  0.330  0.068  1.0
  O  O16  1  0.692  0.846  0.574  1.0
  O  O17  1  0.839  0.161  0.431  1.0
  O  O18  1  0.670  0.835  0.068  1.0
  O  O19  1  0.505  0.495  0.295  1.0
  O  O20  1  0.154  0.308  0.574  1.0
  O  O21  1  0.839  0.677  0.431  1.0
  O  O22  1  0.330  0.165  0.931  1.0
  O  O23  1  0.505  0.495  0.695  1.0
  O  O24  1  0.154  0.846  0.574  1.0
  O  O25  1  0.323  0.161  0.431  1.0
  O  O26  1  0.835  0.670  0.931  1.0
  O  O27  1  0.505  0.010  0.695  1.0
  O  O28  1  0.835  0.165  0.931  1.0
  O  O29  1  0.990  0.495  0.695  1.0
[/CIF]
.
The material structure described by Ba3UHoFeO9 crystallizes in the trigonal P3m1 space group. There are six inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a distorted q6 geometry to three equivalent O(5) and six equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded to three equivalent O(2), three equivalent O(3), and six equivalent O(4) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(2)O12 cuboctahedra,  a faceface with one Fe(1)O6 octahedra, faces with three equivalent U(2)O6 octahedra, and faces with three equivalent Fe(2)O6 octahedra. In the third Ba site, Ba(3) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. In the fourth Ba site, Ba(4) is bonded in a distorted q6 geometry to three equivalent O(4) and six equivalent O(2) atoms. In the fifth Ba site, Ba(5) is bonded in a distorted hexagonal planar geometry to three equivalent O(5) and three equivalent O(6) atoms. In the sixth Ba site, Ba(6) is bonded in a distorted q6 geometry to three equivalent O(1) and six equivalent O(5) atoms. There are two inequivalent U sites. In the first U site, U(1) is bonded in an octahedral geometry to three equivalent O(1) and three equivalent O(5) atoms. In the second U site, U(2) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form UO6 octahedra that share corners with three equivalent Fe(2)O6 octahedra and faces with three equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 3-coordinate geometry to three equivalent O(3) and six equivalent O(6) atoms. In the second Ho site, Ho(2) is bonded in a 3-coordinate geometry to three equivalent O(6) and six equivalent O(3) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form FeO6 octahedra that share corners with three equivalent Fe(2)O6 octahedra and  a faceface with one Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 6°. In the second Fe site, Fe(2) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form FeO6 octahedra that share corners with three equivalent U(2)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and faces with three equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-6°. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Ba(3), one Ba(6), two equivalent Ba(1), and one U(1) atom to form a mixture of distorted edge, face, and corner-sharing OBa4U square pyramids. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(4), and one U(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Ba(2), one Ho(1), two equivalent Ho(2), one Fe(1), and one Fe(2) atom. In the fourth O site, O(4) is bonded to one Ba(4), two equivalent Ba(2), one U(2), and one Fe(2) atom to form a mixture of distorted edge, face, and corner-sharing OBa3UFe square pyramids. In the fifth O site, O(5) is bonded to one Ba(1), one Ba(5), two equivalent Ba(6), and one U(1) atom to form a mixture of distorted edge, face, and corner-sharing OBa4U square pyramids. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ba(5), one Ho(2), two equivalent Ho(1), and one Fe(1) atom. is represented by the CIF file [CIF]
data_Ba3HoUFeO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.994
_cell_length_b   5.994
_cell_length_c   17.327
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   539.060
_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
  Ba  Ba0  1  0.667  0.333  0.052  1.0
  Ba  Ba1  1  0.333  0.667  0.446  1.0
  Ba  Ba2  1  0.333  0.667  0.182  1.0
  Ba  Ba3  1  0.000  0.000  0.304  1.0
  Ba  Ba4  1  0.667  0.333  0.815  1.0
  Ba  Ba5  1  0.333  0.667  0.945  1.0
  Ho  Ho6  1  0.000  0.000  0.658  1.0
  Ho  Ho7  1  0.667  0.333  0.615  1.0
  U  U8  1  0.000  0.000  0.999  1.0
  U  U9  1  0.667  0.333  0.362  1.0
  Fe  Fe10  1  0.333  0.667  0.646  1.0
  Fe  Fe11  1  0.000  0.000  0.497  1.0
  O  O12  1  0.165  0.835  0.068  1.0
  O  O13  1  0.990  0.495  0.295  1.0
  O  O14  1  0.505  0.010  0.295  1.0
  O  O15  1  0.165  0.330  0.068  1.0
  O  O16  1  0.692  0.846  0.574  1.0
  O  O17  1  0.839  0.161  0.431  1.0
  O  O18  1  0.670  0.835  0.068  1.0
  O  O19  1  0.505  0.495  0.295  1.0
  O  O20  1  0.154  0.308  0.574  1.0
  O  O21  1  0.839  0.677  0.431  1.0
  O  O22  1  0.330  0.165  0.931  1.0
  O  O23  1  0.505  0.495  0.695  1.0
  O  O24  1  0.154  0.846  0.574  1.0
  O  O25  1  0.323  0.161  0.431  1.0
  O  O26  1  0.835  0.670  0.931  1.0
  O  O27  1  0.505  0.010  0.695  1.0
  O  O28  1  0.835  0.165  0.931  1.0
  O  O29  1  0.990  0.495  0.695  1.0
[/CIF]
.