Molecular self-assembly directed by non-covalent interactions presents a unique opportunity to create precisely engineered functional materials. Halogen bonding is a widely studied interaction in three dimensions but there is limited research in two dimensions. Previous work in the Clarke group has focused structural determination of monolayers on graphite using two-dimensional diffraction; however, this technique can be insensitive to orientation perpendicular to the surface. We propose to measure the gamma resonance spectrum for I2 on graphite with the incident neutron beam parallel and perpendicular to the graphite surface. Comparison of the mean kinetic energies of the iodine atoms in these directions allows for determination of the orientation of the molecule with respect to the surface.