Extraction of tunneling splittings from a real time semiclassical propagation

The long-standing question of whether the tunneling effects can be recovered from a real time semiclassical propagation is addressed. Even at very low energies below the barrier for symmetric one- and two-dimensional double wells the tunneling splittings are accurately computed using harmonic inversion of the time cross-correlation matrix by the filter-diagonalization method. The time propagation is carried out using the Herman–Kluk propagator.