The material described by NbFe5(PO4)6 crystallizes in the trigonal R3 space group. Nb(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form NbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Fe(1)O6 octahedra. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(2) and three equivalent O(6) atoms to form distorted FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Nb(1)O6 octahedra, and  a faceface with one Fe(4)O6 octahedra. In the second Fe site, Fe(2) is bonded to three equivalent O(4) and three equivalent O(8) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Fe(3)O6 octahedra. In the third Fe site, Fe(3) is bonded to three equivalent O(4) and three equivalent O(7) atoms to form distorted FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Fe(2)O6 octahedra, and  a faceface with one Fe(5)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Fe(1)O6 octahedra. In the fifth Fe site, Fe(5) is bonded to three equivalent O(1) and three equivalent O(7) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Fe(3)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, and  a cornercorner with one Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-52°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, and  a cornercorner with one Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-48°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(5) and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(4), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Fe(2), one Fe(3), and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(4) and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Nb(1), one Fe(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Fe(3), one Fe(5), and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. is represented by the CIF file [CIF]
data_NbFe5(PO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.586
_cell_length_b   8.586
_cell_length_c   8.586
_cell_angle_alpha   61.017
_cell_angle_beta   61.017
_cell_angle_gamma   61.017
_symmetry_Int_Tables_number   1
_cell_volume   457.837
_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
  Nb  Nb0  1  0.858  0.858  0.858  1.0
  Fe  Fe1  1  0.004  0.004  0.004  1.0
  Fe  Fe2  1  0.357  0.357  0.357  1.0
  Fe  Fe3  1  0.501  0.501  0.501  1.0
  Fe  Fe4  1  0.145  0.145  0.145  1.0
  Fe  Fe5  1  0.643  0.643  0.643  1.0
  P  P6  1  0.747  0.045  0.451  1.0
  P  P7  1  0.045  0.451  0.747  1.0
  P  P8  1  0.451  0.747  0.045  1.0
  P  P9  1  0.538  0.256  0.957  1.0
  P  P10  1  0.957  0.538  0.256  1.0
  P  P11  1  0.256  0.957  0.538  1.0
  O  O12  1  0.889  0.497  0.681  1.0
  O  O13  1  0.497  0.681  0.889  1.0
  O  O14  1  0.681  0.889  0.497  1.0
  O  O15  1  0.909  0.060  0.260  1.0
  O  O16  1  0.818  0.993  0.615  1.0
  O  O17  1  0.592  0.240  0.446  1.0
  O  O18  1  0.060  0.260  0.909  1.0
  O  O19  1  0.240  0.446  0.592  1.0
  O  O20  1  0.389  0.180  0.998  1.0
  O  O21  1  0.446  0.592  0.240  1.0
  O  O22  1  0.739  0.093  0.937  1.0
  O  O23  1  0.998  0.389  0.180  1.0
  O  O24  1  0.993  0.615  0.818  1.0
  O  O25  1  0.260  0.909  0.060  1.0
  O  O26  1  0.558  0.410  0.760  1.0
  O  O27  1  0.615  0.818  0.993  1.0
  O  O28  1  0.760  0.558  0.410  1.0
  O  O29  1  0.937  0.739  0.093  1.0
  O  O30  1  0.410  0.760  0.558  1.0
  O  O31  1  0.180  0.998  0.389  1.0
  O  O32  1  0.093  0.937  0.739  1.0
  O  O33  1  0.315  0.113  0.506  1.0
  O  O34  1  0.506  0.315  0.113  1.0
  O  O35  1  0.113  0.506  0.315  1.0
[/CIF]
.
The material described by NbFe5(PO4)6 crystallizes in the trigonal R3 space group. Nb(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form NbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Fe(1)O6 octahedra. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(2) and three equivalent O(6) atoms to form distorted FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Nb(1)O6 octahedra, and  a faceface with one Fe(4)O6 octahedra. In the second Fe site, Fe(2) is bonded to three equivalent O(4) and three equivalent O(8) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Fe(3)O6 octahedra. In the third Fe site, Fe(3) is bonded to three equivalent O(4) and three equivalent O(7) atoms to form distorted FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Fe(2)O6 octahedra, and  a faceface with one Fe(5)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Fe(1)O6 octahedra. In the fifth Fe site, Fe(5) is bonded to three equivalent O(1) and three equivalent O(7) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Fe(3)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, and  a cornercorner with one Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-52°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, and  a cornercorner with one Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-48°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(5) and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(4), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Fe(2), one Fe(3), and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(4) and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Nb(1), one Fe(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Fe(3), one Fe(5), and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. is represented by the CIF file [CIF]
data_NbFe5(PO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.586
_cell_length_b   8.586
_cell_length_c   8.586
_cell_angle_alpha   61.017
_cell_angle_beta   61.017
_cell_angle_gamma   61.017
_symmetry_Int_Tables_number   1
_cell_volume   457.837
_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
  Nb  Nb0  1  0.858  0.858  0.858  1.0
  Fe  Fe1  1  0.004  0.004  0.004  1.0
  Fe  Fe2  1  0.357  0.357  0.357  1.0
  Fe  Fe3  1  0.501  0.501  0.501  1.0
  Fe  Fe4  1  0.145  0.145  0.145  1.0
  Fe  Fe5  1  0.643  0.643  0.643  1.0
  P  P6  1  0.747  0.045  0.451  1.0
  P  P7  1  0.045  0.451  0.747  1.0
  P  P8  1  0.451  0.747  0.045  1.0
  P  P9  1  0.538  0.256  0.957  1.0
  P  P10  1  0.957  0.538  0.256  1.0
  P  P11  1  0.256  0.957  0.538  1.0
  O  O12  1  0.889  0.497  0.681  1.0
  O  O13  1  0.497  0.681  0.889  1.0
  O  O14  1  0.681  0.889  0.497  1.0
  O  O15  1  0.909  0.060  0.260  1.0
  O  O16  1  0.818  0.993  0.615  1.0
  O  O17  1  0.592  0.240  0.446  1.0
  O  O18  1  0.060  0.260  0.909  1.0
  O  O19  1  0.240  0.446  0.592  1.0
  O  O20  1  0.389  0.180  0.998  1.0
  O  O21  1  0.446  0.592  0.240  1.0
  O  O22  1  0.739  0.093  0.937  1.0
  O  O23  1  0.998  0.389  0.180  1.0
  O  O24  1  0.993  0.615  0.818  1.0
  O  O25  1  0.260  0.909  0.060  1.0
  O  O26  1  0.558  0.410  0.760  1.0
  O  O27  1  0.615  0.818  0.993  1.0
  O  O28  1  0.760  0.558  0.410  1.0
  O  O29  1  0.937  0.739  0.093  1.0
  O  O30  1  0.410  0.760  0.558  1.0
  O  O31  1  0.180  0.998  0.389  1.0
  O  O32  1  0.093  0.937  0.739  1.0
  O  O33  1  0.315  0.113  0.506  1.0
  O  O34  1  0.506  0.315  0.113  1.0
  O  O35  1  0.113  0.506  0.315  1.0
[/CIF]
.