BaNb2(FeO3)4 crystallizes in the tetragonal I4/m space group. Ba(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. Nb(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra and edges with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-52°. Fe(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, edges with two equivalent Nb(1)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-52°. There are four inequivalent O sites. In the first O site, O(2) is bonded to one Ba(1), one Nb(1), and two equivalent Fe(1) atoms to form a mixture of distorted edge and corner-sharing OBaNbFe2 trigonal pyramids. In the second O site, O(3) is bonded in a distorted trigonal planar geometry to one Nb(1) and two equivalent Fe(1) atoms. In the third O site, O(4) is bonded in a distorted trigonal planar geometry to one Nb(1) and two equivalent Fe(1) atoms. In the fourth O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one Nb(1), and two equivalent Fe(1) atoms.
BaNb2(FeO3)4 crystallizes in the tetragonal I4/m space group. Ba(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. All Ba(1)-O(1) bond lengths are 3.19 Å. All Ba(1)-O(2) bond lengths are 2.77 Å. Nb(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra and edges with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-52°. The Nb(1)-O(1) bond length is 2.14 Å. The Nb(1)-O(3) bond length is 1.93 Å. Both Nb(1)-O(2) bond lengths are 2.09 Å. Both Nb(1)-O(4) bond lengths are 1.95 Å. Fe(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, edges with two equivalent Nb(1)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-52°. The Fe(1)-O(1) bond length is 1.98 Å. The Fe(1)-O(3) bond length is 1.95 Å. There is one shorter (1.94 Å) and one longer (1.99 Å) Fe(1)-O(2) bond length. There is one shorter (1.95 Å) and one longer (2.00 Å) Fe(1)-O(4) bond length. There are four inequivalent O sites. In the first O site, O(2) is bonded to one Ba(1), one Nb(1), and two equivalent Fe(1) atoms to form a mixture of distorted edge and corner-sharing OBaNbFe2 trigonal pyramids. In the second O site, O(3) is bonded in a distorted trigonal planar geometry to one Nb(1) and two equivalent Fe(1) atoms. In the third O site, O(4) is bonded in a distorted trigonal planar geometry to one Nb(1) and two equivalent Fe(1) atoms. In the fourth O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one Nb(1), and two equivalent Fe(1) atoms.