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We have performed a nuclear dynamics simulation to calculate photoelectron spectra and population profiles of benzene radical cation (CH $_6^+$) employing the parallelized Time Dependent Discrete Variable Representation (TDDVR) approach. For this purpose, we have considered two multi-state multi-mode model Hamiltonians of CH $_6^+$ with degeneracy among the eectronic states: (a) One consists of three states and eight modes, which in turn leads to a five state thirteen mode Hamiltonian ( XE- BE- CA) due to the degeneracy; and (b) The other is constituted of three states and thirteen modes which is basically a five state twenty mode Hamiltonian ( BE- DE- EB) for the same reason. Since these electronic states are interconnected by several conical intersections in the vicinity of the Franck Condon region, it will be challenging to pursue such large dynamical calculation in the presence of nonadiabaticity among the electronic states. The spectral as well as population profiles calculated with the advent of TDDVR approach show reasonably good agreement with the results obtained by the Multi Configuration Time Dependent Hartree (MCTDH) methodology. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Vibrational excitation cross-sections $\sigma_{\nu_f \leftarrow \nu_i } (E)$ in resonant e-F and HCl scattering are calculated from transition matrix elements $T_{\nu_f \leftarrow \nu_i } (E)$ obtained using Fourier transform of the cross correlation function $\left\langle {\phi_{\nu_f } \left( R \right)\vert \Psi_{\nu_i } \left( {R,t} \right)} \right\rangle $ where $\Psi_{\nu_i } \left( {R,t} \right)\approx e^{-i\hbar H_{AB^-} \left( R \right)t}\phi_{\nu { }_i} \left( R \right)$. Time evolution under the influence of the resonance anionic Hamiltonian H- (AB=F/HCl) is effected using Lanczos reduction technique followed by fast Fourier transform and the target (AB) vibrational eigenfunctions $\phi _{\nu_i } \left( R \right)$ and $\phi_{\nu_f } \left( R \right)$ are calculated using Fourier grid Hamiltonian method applied to potential energy (PE) curve of the neutral target. The resulting vibrational excitation cross-sections provide reasonable agreement with experimental and other theoretical results. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

By treating the non-adiabatic coupling terms (NACTs) in a molecular system as equivalent to a frictional force, the classical equation of motion is solved for a test case of quasi-H3+ along the C2v axis and axes parallel to it, and it is shown that the singular NACTs between the first two excited electronic states slow down the relative motion of the three quasi-ions (H,H,H)+ while approaching each other. [ABSTRACT FROM AUTHOR]

Results from application of a new implementation of the time-dependent wave packet (TDWP) approach to the calculation of vibrational excitation cross-sections in resonant e-CO scattering are presented to examine its applicability in the treatment of e-molecule resonances. The results show that the SCF level local complex potential (LCP) in conjunction with the TDWP approach can reproduce experimental features quite satisfactorily. [ABSTRACT FROM AUTHOR]