Fe2(PO4)O crystallizes in the tetragonal I4_1/amd space group. Fe(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. P(1) is bonded to four equivalent O(2) atoms to form PO4 tetrahedra that share corners with eight equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 41°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to four equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one P(1) atom.
Fe2(PO4)O crystallizes in the tetragonal I4_1/amd space group. Fe(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. Both Fe(1)-O(1) bond lengths are 2.08 Å. All Fe(1)-O(2) bond lengths are 2.09 Å. P(1) is bonded to four equivalent O(2) atoms to form PO4 tetrahedra that share corners with eight equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 41°. All P(1)-O(2) bond lengths are 1.55 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to four equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one P(1) atom.