MnFeBiO5 crystallizes in the orthorhombic Pbam space group. Mn(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form MnO5 square pyramids that share corners with four equivalent Fe(1)O6 octahedra and  an edgeedge with one Mn(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 48-56°. Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with four equivalent Mn(1)O5 square pyramids and edges with two equivalent Fe(1)O6 octahedra. Bi(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Mn(1) and two equivalent Fe(1) atoms. In the second O site, O(2) is bonded to two equivalent Fe(1) and two equivalent Bi(1) atoms to form a mixture of distorted corner and edge-sharing OFe2Bi2 trigonal pyramids. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mn(1), one Fe(1), and two equivalent Bi(1) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Mn(1) and two equivalent Bi(1) atoms.
MnFeBiO5 crystallizes in the orthorhombic Pbam space group. Mn(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form MnO5 square pyramids that share corners with four equivalent Fe(1)O6 octahedra and  an edgeedge with one Mn(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 48-56°. The Mn(1)-O(1) bond length is 1.90 Å. Both Mn(1)-O(3) bond lengths are 1.94 Å. Both Mn(1)-O(4) bond lengths are 1.94 Å. Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with four equivalent Mn(1)O5 square pyramids and edges with two equivalent Fe(1)O6 octahedra. Both Fe(1)-O(1) bond lengths are 2.00 Å. Both Fe(1)-O(2) bond lengths are 2.03 Å. Both Fe(1)-O(3) bond lengths are 2.01 Å. Bi(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms. Both Bi(1)-O(2) bond lengths are 2.37 Å. Both Bi(1)-O(4) bond lengths are 2.58 Å. There are two shorter (2.29 Å) and two longer (2.82 Å) Bi(1)-O(3) bond lengths. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Mn(1) and two equivalent Fe(1) atoms. In the second O site, O(2) is bonded to two equivalent Fe(1) and two equivalent Bi(1) atoms to form a mixture of distorted corner and edge-sharing OFe2Bi2 trigonal pyramids. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mn(1), one Fe(1), and two equivalent Bi(1) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Mn(1) and two equivalent Bi(1) atoms.