BaNb2Fe2(PO4)6 crystallizes in the trigonal R3 space group. Ba(1) is bonded in a distorted hexagonal planar geometry to three equivalent O(5) and three equivalent O(7) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to three equivalent O(3) and three equivalent O(7) atoms to form NbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. In the second Nb site, Nb(2) is bonded to three equivalent O(4) and three equivalent O(8) atoms to form NbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(1) and three equivalent O(5) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to three equivalent O(2) and three equivalent O(6) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and  a cornercorner with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-32°. In the second P site, P(2) is bonded to one O(2), one O(3), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and  a cornercorner with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-32°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ba(1), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Nb(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(2) atom.
BaNb2Fe2(PO4)6 crystallizes in the trigonal R3 space group. Ba(1) is bonded in a distorted hexagonal planar geometry to three equivalent O(5) and three equivalent O(7) atoms. All Ba(1)-O(5) bond lengths are 2.69 Å. All Ba(1)-O(7) bond lengths are 2.85 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to three equivalent O(3) and three equivalent O(7) atoms to form NbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Nb(1)-O(3) bond lengths are 1.98 Å. All Nb(1)-O(7) bond lengths are 2.03 Å. In the second Nb site, Nb(2) is bonded to three equivalent O(4) and three equivalent O(8) atoms to form NbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Nb(2)-O(4) bond lengths are 2.03 Å. All Nb(2)-O(8) bond lengths are 1.97 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(1) and three equivalent O(5) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Fe(1)-O(1) bond lengths are 1.95 Å. All Fe(1)-O(5) bond lengths are 2.08 Å. In the second Fe site, Fe(2) is bonded to three equivalent O(2) and three equivalent O(6) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Fe(2)-O(2) bond lengths are 2.04 Å. All Fe(2)-O(6) bond lengths are 1.98 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and  a cornercorner with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-32°. The P(1)-O(1) bond length is 1.51 Å. The P(1)-O(4) bond length is 1.58 Å. The P(1)-O(6) bond length is 1.51 Å. The P(1)-O(7) bond length is 1.59 Å. In the second P site, P(2) is bonded to one O(2), one O(3), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and  a cornercorner with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-32°. The P(2)-O(2) bond length is 1.52 Å. The P(2)-O(3) bond length is 1.57 Å. The P(2)-O(5) bond length is 1.53 Å. The P(2)-O(8) bond length is 1.57 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ba(1), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Nb(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(2) atom.