FePO4 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(4) atoms to form FeO5 trigonal bipyramids that share corners with five equivalent 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 five equivalent Fe(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Fe(1) and one P(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 bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one P(1) atom.
FePO4 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(4) atoms to form FeO5 trigonal bipyramids that share corners with five equivalent P(1)O4 tetrahedra and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The Fe(1)-O(1) bond length is 1.86 Å. The Fe(1)-O(2) bond length is 1.87 Å. The Fe(1)-O(3) bond length is 1.91 Å. There is one shorter (1.98 Å) and one longer (2.17 Å) Fe(1)-O(4) 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 five equivalent Fe(1)O5 trigonal bipyramids. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.57 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Fe(1) and one P(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 bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one P(1) atom.