Fe(OH)HPO4 crystallizes in the monoclinic C2/c space group. 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 two equivalent Fe(1)O6 octahedra and corners with four equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-49°. H(1) is bonded in a distorted single-bond geometry to one O(1) and one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Fe(1), one P(1), and one H(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 distorted water-like geometry to two equivalent Fe(1) and two equivalent H(1) atoms.
Fe(OH)HPO4 crystallizes in the monoclinic C2/c space group. 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 two equivalent Fe(1)O6 octahedra and corners with four equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. Both Fe(1)-O(1) bond lengths are 2.01 Å. Both Fe(1)-O(2) bond lengths are 1.93 Å. Both Fe(1)-O(3) bond lengths are 2.22 Å. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-49°. Both P(1)-O(1) bond lengths are 1.56 Å. Both P(1)-O(2) bond lengths are 1.54 Å. H(1) is bonded in a distorted single-bond geometry to one O(1) and one O(3) atom. The H(1)-O(1) bond length is 1.67 Å. The H(1)-O(3) bond length is 1.02 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Fe(1), one P(1), and one H(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 distorted water-like geometry to two equivalent Fe(1) and two equivalent H(1) atoms.