FePO4 crystallizes in the monoclinic Pc space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent P(2)O4 tetrahedra and  an edgeedge with one P(1)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form FeO4 tetrahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O4 tetrahedra and  an edgeedge with one Fe(1)O4 tetrahedra. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra and corners with two equivalent Fe(2)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Fe(2) 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(2) atom. In the fourth O site, O(4) is bonded in an L-shaped geometry to one Fe(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the eighth O site, O(8) is bonded in an L-shaped geometry to one Fe(1) and one P(1) atom.
FePO4 crystallizes in the monoclinic Pc space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent P(2)O4 tetrahedra and  an edgeedge with one P(1)O4 tetrahedra. The Fe(1)-O(1) bond length is 1.89 Å. The Fe(1)-O(3) bond length is 1.89 Å. The Fe(1)-O(4) bond length is 1.96 Å. The Fe(1)-O(8) bond length is 1.97 Å. In the second Fe site, Fe(2) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form FeO4 tetrahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. The Fe(2)-O(2) bond length is 1.90 Å. The Fe(2)-O(5) bond length is 1.88 Å. The Fe(2)-O(6) bond length is 1.90 Å. The Fe(2)-O(7) bond length is 1.89 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O4 tetrahedra and  an edgeedge with one Fe(1)O4 tetrahedra. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.58 Å. The P(1)-O(7) bond length is 1.55 Å. The P(1)-O(8) bond length is 1.57 Å. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra and corners with two equivalent Fe(2)O4 tetrahedra. The P(2)-O(1) bond length is 1.55 Å. The P(2)-O(3) bond length is 1.55 Å. The P(2)-O(5) bond length is 1.56 Å. The P(2)-O(6) bond length is 1.54 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Fe(2) 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(2) atom. In the fourth O site, O(4) is bonded in an L-shaped geometry to one Fe(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the eighth O site, O(8) is bonded in an L-shaped geometry to one Fe(1) and one P(1) atom.