MnPO4 crystallizes in the triclinic P-1 space group. Mn(1) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form MnO5 trigonal bipyramids that share corners with five equivalent P(1)O4 tetrahedra and  an edgeedge with one Mn(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 Mn(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Mn(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Mn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one P(1) atom.
MnPO4 crystallizes in the triclinic P-1 space group. Mn(1) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form MnO5 trigonal bipyramids that share corners with five equivalent P(1)O4 tetrahedra and  an edgeedge with one Mn(1)O5 trigonal bipyramid. The Mn(1)-O(1) bond length is 1.89 Å. The Mn(1)-O(2) bond length is 2.02 Å. The Mn(1)-O(4) bond length is 1.92 Å. There is one shorter (2.00 Å) and one longer (2.09 Å) Mn(1)-O(3) 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 Mn(1)O5 trigonal bipyramids. The P(1)-O(1) bond length is 1.56 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.60 Å. The P(1)-O(4) bond length is 1.55 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Mn(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Mn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one P(1) atom.