On the Zero Point Energy Difficulty of Quasiclassical Trajectory Simulations

Following the work of Guo, Thompson, and Sewell (Y.Guo, D.L.Thompson, and T.D. Sewell, J.Chem.Phys. 104, 576 (1996)) on the zero point energy correction of classical trajectories, we emphasize that the zero-point energy of a molecule is a quantum phenomenon with no classical counterpart, rooted soundly in the positionmomentum uncertainty principle. As a consequence certain quantum “ingredients,” such as those introduced using Heller’s thawed Gaussian wavepacket dynamics (E.J. Heller, J.Chem.Phys. 62, 1544 (1975)), are probably necessary to avoid the computational difficulties in applying zero-point energy corrections to classical molecular dynamics trajectories which have been described in the literature to date.