FePO4 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted FeO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. 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 three equivalent Fe(1)O5 trigonal bipyramids and  an edgeedge with one Fe(1)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to two equivalent Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a water-like geometry to one Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 120 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.
FePO4 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted FeO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The Fe(1)-O(2) bond length is 1.98 Å. The Fe(1)-O(3) bond length is 1.92 Å. The Fe(1)-O(4) bond length is 1.87 Å. There is one shorter (2.05 Å) and one longer (2.14 Å) Fe(1)-O(1) bond length. 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 three equivalent Fe(1)O5 trigonal bipyramids and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The P(1)-O(1) bond length is 1.58 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(4) bond length is 1.53 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to two equivalent Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a water-like geometry to one Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 120 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.