Since the observation of two intermolecular translational optic peaks at 28 and 37 meV using inelastic neutron scattering techniques, there has been a renewed effort to reproduce phonon density of states with these peaks by computer simulation. In this paper, we demonstrate our attempt to calculate the measured inelastic neutron spectrum using molecular dynamic techniques for a number of potentials, such as TIP4P, MCY, and KKY potentials. The results show that none of them can reproduce the double peaks seen in the measured spectrum.