title: On-the-fly semiclassical study of internal conversion rates of formaldehyde.
abstract: Internal conversion is an inherently quantum mechanical process. To date, "ab initio" computation of internal conversion rates was limited to harmonic based approximations. These are questionable since the typical transition to the ground electronic state occurs at energies which are far from the harmonic limit. It is thus of interest to study the applicability of the Semiclassical Initial Value Representation (SCIVR) approach which is in principle amenable to "on the fly" studies even with "many" degrees of freedom. In this work we apply the Herman-Kluk-SCIVR methodology to compute the internal conversion rates for formaldehyde for a variety of initial vibronic states. The SCIVR computation gives reasonable agreement with experiment, while the harmonic approximation typically gives rates that are too high.
authors.affiliation: Shenkar College of Engineering and Design and Chemical Physics Department, Weizmann Institute of Science, 76100 Rehovoth, Israel.
authors.forename: Reuven
authors.initials: R
authors.lastname: Ianconescu
authors.forename: Jörg
authors.initials: J
authors.lastname: Tatchen
authors.forename: Eli
authors.initials: E
authors.lastname: Pollak