Vibrational autoionization in polyatomic molecules.

Selection rules for vibrational energy loss by resonant electron impact in polyatomic molecules.

Vibrational spectra of polyatomic molecules assisted by quantum thermal baths.

We assess the performance of colored-noise thermostats to generate quantum mechanical initial conditions for molecular dynamics simulations, in the context of infrared spectra of large polyatomic molecules. Comparison with centroid molecular dynamics simulations taken as reference shows that the method is accurate in predicting line shifts and band widths in the ionic cluster (NaCl)(32) and in ...

Degenerate perturbation theory corrections for the vibrational self-consistent field approximation: Method and applications

A new algorithm for computing anharmonic vibrational states for polyatomic molecules is proposed. The algorithm starts with the vibrational self-consistent field ~VSCF! method and uses degenerate perturbation theory to correct for effects of correlation between different vibrational modes. The algorithm is developed in a version that computes the anharmonic vibrational spectroscopy directly fro...

Extensive electron-nuclear angular momentum exchange in vibrational autoionization of np and nf Rydberg states of NO.

Vibrational autoionization of individual rotational levels of np (n ­ 1) and nf (n ­ 1) Rydberg states of nitric oxide (NO) with 11 # n # 15 have been studied employing two-color double-resonance excitation via the NO A S1 (ni ­ 1) state. The rotational state distributions of the resulting NO X S1 (n ­ 0) ion have been determined by time-of-flight photoelectron spectroscopy. These measurements ...

Excited-state vibrational coherence of solution-phase molecules observed in the third-order optical process using extremely short pulses

Excited-state vibrational coherence of solution-phase polyatomic molecules was studied by two different timedomain spectroscopic methods. Raman-active low-frequency vibrations in the excited state of trans-stilbene were observed by transient impulsive stimulated Raman scattering spectroscopy. In transient absorption spectroscopy with a 40-fs resolution, a different vibrational mode of the same ...