FePO6 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted FeO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra. 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 corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-40°. There are six 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(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Fe(1) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Fe(1) atom.
FePO6 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted FeO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra. The Fe(1)-O(1) bond length is 1.99 Å. The Fe(1)-O(2) bond length is 1.95 Å. The Fe(1)-O(3) bond length is 1.99 Å. The Fe(1)-O(4) bond length is 1.94 Å. The Fe(1)-O(5) bond length is 2.05 Å. The Fe(1)-O(6) bond length is 2.14 Å. 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 corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-40°. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(4) bond length is 1.52 Å. There are six 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(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Fe(1) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Fe(1) atom.