XXXVI Reunión Bienal de la Real Sociedad Española de Física

Energy transfer in gaseous mixtures for atmospheric and astrochemical modelling

18 jul. 2017 16:25

20m

Aula Matemáticas (Facultad de Química (USC))

Oral parallel contribution Molecular Physics at the Edge Molecular Physics at the Edge I

Descripción

The development of realistic kinetic models of gaseous systems is a fundamental issue in the study of Earth and planetary atmospheres, plasma chemistry, gas flows and astrochemistry. Particularly, the adoption of a state-to-state level of detail in the description of the molecular energy transfer [1,2], a desirable and necessary improvement, requires much insight into the dynamics of the inelastic collisions and the prompt availability of state-specific energy transfer probabilities and rate coefficients. Existing venerable approximated theories of the energy transfer, such as the Schwartz-Slawsky-Herzfeld one, are not really state-specific and have limited validity. Therefore probabilities and cross sections have to be calculated directly by simulation of the dynamics of the molecular collisions. The reliability of the simulations is conditional to the availability of accurate descriptions of the intermolecular interactions occurring between pairs of the molecular species present in the gas mixture. Here, we present examples of calculation of rate coefficients of energy transfer in mixtures containing CO2 and N2 [3-6] obtained applying a semiempirical approach to the interaction modelling, based on (i) a physically meaningful partition of the contribution to the interaction, (ii) the use of data from molecular beam experiments and (iii) ab initio calculations. An extension of such an approach can be also applied to the modelling dynamics and kinetics of gas-surface systems. Acknowledgments A. L. acknowledges financial support from the Dipartimento di Chimica, Biologia e Biotecnologie dellUniversita di Perugia (FRB, Fondo per la Ricerca di Base), from MIUR PRIN 2010/2011 (contract 2010ERFKXL 002) and from “Fondazione Cassa Risparmio Perugia (Codice Progetto: 2015.0331.021 Ricerca Scientifica e Tecnologica)”. A. L. and F. P. acknowledge the Italian Ministry for Education, University and Research, MIUR, for financial supporting: SIR 2014 “Scientific Independence for young Researchers” (RBSI14U3VF) and financial support from MIUR PRIN 2015 (contract 2015F59J3R 002). References [1] Capitelli, M., Ferreira, C. M., Gordiets, B. F., Osipov, R.: Plasma kinetics in atmospheric gases; Springer Verlag, 2000. [2] E. Kustova, E. Nagnibeda, State-to-state theory of vibrational kinetics and dissociation in three-atomic gases; In Rarefied Gas Dynamics; T. Bartel, M. Gallis, Eds.; AIP Conference Proceedings, Vol. 585, pp. 620–627, IOP Publishing, Bristol, England, 2001. 
[3] M. Bartolomei, F. Pirani, A. Lagana, A. Lombardi, A full dimensional grid empowered simulation of the CO2 + CO2 processes, J. Comput. Chem. 33 (2012) 1806. [4] A. Lombardi, N. Faginas Lago, A. Laganà, F. Pirani, S. Falcinelli, Lecture Notes in Computer Science 7333 Part I (2012) 387. [5] A. Lombardi, N. Faginas-Lago, L. Pacifici, A. Costantini, Modeling of energy transfer from vibrationally excited CO2 molecules: cross sections and probabilities for kinetic modeling of atmospheres, flows, and plasmas, J. Phys. Chem. A 117 (2013) 11430. [6] A. Lombardi, F. Pirani, A. Laganà, M. Bartolomei Energy Transfer Dynamics and Kinetics of Elementary Processes (Promoted) by Gas-Phase CO2-N2 Collisions: Selectivity Control by the Anisotropy of the Interaction 33 J. Comp. Chem. (2016) 1463.