Spectral manifestation of stochaticity in molecular systems.
Development of theoretical methods for simulation of complex molecule spectra
Savva V.A., Zalesskaya G.A., Kotomtseva L.A., Nizovtsev A.P., Turovets S.I.,
Mazurenko A.S., Yakovlev D.L., Dolya Z.E., Rusov S.G.
Estimations to apply Riemann geometry methods were made to describe Hamiltonian chaos in the classical dynamics of small molecules. Program package was elaborated for simulations of molecular dynamics by method of classical trajectories.For modeling complex dynamics of a molecule in quantum description model multilevel Krawchuk systems with degenerated energy levels have been constructed. Analytic solution of equa-tions which describe quantum dynamics of such systems in field of power laser radiation is obtained. It has been shown the population dynamics of a several sublevel can be very complex. Formation of ensembles of particles with different speeds of excitation has been demonstrated.
Method with using orthogonal functions for obtaining exact analytical solutions of equations which model quantum molecular dynamics in multifrequency laser field has been constructed.
An optically detected coherent response of a single triplet-state chromophore guest molecule in a low-temperature crystalline organic host matrix to microwave radiation, which is in near reso-nance with the transition between sublevels of its triplet state, is studied using stochastic approach to describe dephasing of the triplet electron spin of the molecule due to its interactions with fluctuating spins of the matrix protons. Exact set of equations for the density matrix of the molecule, averaged the fluctuations histories, is constructed. Both frequency- and time-domain optically detected mag-netic resonance (ODMR) phenomena such as (i) power-broadened ODMR line shapes, (ii) ODMR Hahn echo and (iii) ODMR free induction decay are studied. Available experimental data for single pentacene molecules in para-terphenyl matrix are described quantitatively.
Complicated regular regimes and dynamical chaos of different structure are described in a bimodal CO2 laser with a saturate absorber.
The influence of the vibrational quasicontinuum structure on the vibrational energy stochasti-zation processes was studied under conditions of quantum energy redistribution among molecular modes. The conditions of interaction with medium (monatomic and polyatomic gases) at which a molecule acts as a complex statistic system were determined.