Semiclassical Tunneling Rates from Ab Initio Molecular Dynamics

Abstract

We demonstrate a new ab initio semiclassical technique for investigating tunneling effects. Using a semiclassical approach, the method incorporates tunneling effects into first principles molecular dynamics. We apply the method to the intramolecular proton transfer in malonaldehyde and find good agreement with the experimentally measured tunneling splitting. This agreement suggests a wide applicability of the new method to proton transfer and coupled electron−proton transfer processes.