FePO4(H2O)2 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 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 30-43°. There are four inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one O(2) and one O(6) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(5) atom. In the third H site, H(3) is bonded in a distorted single-bond geometry to one O(3) and one O(6) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(5) atom. There are six inequivalent O sites. In the first O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Fe(1), one P(1), and one H(3) atom. In the second O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the third O site, O(5) is bonded in a distorted water-like geometry to one Fe(1), one H(2), and one H(4) atom. In the fourth O site, O(6) is bonded in a distorted water-like geometry to one Fe(1), one H(1), and one H(3) atom. In the fifth O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the sixth O site, O(2) is bonded in a 3-coordinate geometry to one Fe(1), one P(1), and one H(1) atom.
FePO4(H2O)2 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 FeO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra. The Fe(1)-O(1) bond length is 1.98 Å. The Fe(1)-O(2) bond length is 2.03 Å. The Fe(1)-O(3) bond length is 2.02 Å. The Fe(1)-O(4) bond length is 1.99 Å. The Fe(1)-O(5) bond length is 2.11 Å. The Fe(1)-O(6) bond length is 2.03 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 30-43°. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.56 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(4) bond length is 1.55 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one O(2) and one O(6) atom. The H(1)-O(2) bond length is 1.69 Å. The H(1)-O(6) bond length is 1.00 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(5) atom. The H(2)-O(5) bond length is 0.99 Å. In the third H site, H(3) is bonded in a distorted single-bond geometry to one O(3) and one O(6) atom. The H(3)-O(3) bond length is 1.65 Å. The H(3)-O(6) bond length is 1.00 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(5) atom. The H(4)-O(5) bond length is 0.98 Å. There are six inequivalent O sites. In the first O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Fe(1), one P(1), and one H(3) atom. In the second O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the third O site, O(5) is bonded in a distorted water-like geometry to one Fe(1), one H(2), and one H(4) atom. In the fourth O site, O(6) is bonded in a distorted water-like geometry to one Fe(1), one H(1), and one H(3) atom. In the fifth O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the sixth O site, O(2) is bonded in a 3-coordinate geometry to one Fe(1), one P(1), and one H(1) atom.