title: Long-time and unitary properties of semiclassical initial value representations.
abstract: We numerically compare the semiclassical "frozen Gaussian" Herman-Kluk propagator [Chem. Phys. 91, 27 (1984)] and the "thawed Gaussian" propagator put forward recently by Baranger et al. [J. Phys. A 34, 7227 (2001)] by studying the quantum dynamics in some nonlinear one-dimensional potentials. The reasons for the lack of long-time accuracy and norm conservation in the latter method are uncovered. We amend the thawed Gaussian propagator with a global harmonic approximation for the stability of the trajectories and demonstrate that this revised propagator is a true alternative to the Herman-Kluk propagator with similar accuracy.
authors.affiliation: Max-Planck Institute for the Physics of Complex Systems, Nothnitzer Strasse 38, D-01187 Dresden, Germany. harabati@mpipks-dresden.mpg.de
authors.forename: C
authors.initials: C
authors.lastname: Harabati
authors.forename: J M
authors.initials: JM
authors.lastname: Rost
authors.forename: F
authors.initials: F
authors.lastname: Grossmann