TY - CONF

T1 - Energy- and Frequency-Corrected Rotational Relaxation Matrix for Binary Collisions between Linear Molecules

AU - Коузов, Александр Петрович

AU - Соколов, Андрей Владимирович

AU - Buldyreva, J.V.

N1 - Conference code: 17

PY - 2018

Y1 - 2018

N2 - From the pioneering work of Anderson [1] on, a variety of fully quantum and semi-quantum versions of linebroadening theory has been elaborated that fostered progress in many spectroscopic applications (analysis of hotgases, combustion, planetary atmospheres, etc). Yet, in these approaches collisions are treated as instantaneousMarkov events (scattering theory) whereas many well-known spectral signatures can be adequately interpretedonly when collisions are supposed to evolve within a finite duration. The relaxation matrix ᴦ, a fundamentalquantity of modern theory, then becomes dependent on frequency ω and its spectrum reflects the intracollisionaldynamics [2]. However, the computational complexity makes the ᴦ(ω)-matrix presently unattainable for directfirst-principle calculations and, hence, development of its simplified dynamically-based models has the pivotalrole for further progress.So far, the ᴦ(ω) spectrum has been mimicked by two similar approaches, the frequency-extended, energycorrected sudden approximation (ECSA) [3] and the fast-collision model [4], which tackled the relaxation problemof a linear rotator immersed into a monoatomic gas. Favourably, both models can be applied to arbitrary rotationalspectra, i.e., ones associated with molecular scalars (isotropic polarizability), vectors (dipoles) and tensors(quadrupoles, etc) thus opening the way to multi-property fittings.Here, extensions of these models to an important case of the nonMarkov collisions between two linear rotatorsare reported. These approaches allow straightforward generalizations to similar collisions between any moleculartops whose rotation is substantially slower than the relative translational motion.References[1] P. W. Anderson, "Pressure Broadening in the Microwave and Infra-Red Regions," Phys. Rev. 76, 647 (1949).[2] U. Fano, "Pressure Broadening as a Prototype of Relaxation," Phys. Rev. 131, 259 (1963).[3] J. V. Buldyreva and L. Bonamy, "Non-Markovian Energy-Corrected Sudden Model for the Rototranslational Spectrum of N2," Phys.Rev. A 60, 370 (1999).[4] A. Kouzov, "Rotational relaxation Matrix for Fast Non-Markovian Collisions," Phys. Rev. A 60, 2931 (1999)

AB - From the pioneering work of Anderson [1] on, a variety of fully quantum and semi-quantum versions of linebroadening theory has been elaborated that fostered progress in many spectroscopic applications (analysis of hotgases, combustion, planetary atmospheres, etc). Yet, in these approaches collisions are treated as instantaneousMarkov events (scattering theory) whereas many well-known spectral signatures can be adequately interpretedonly when collisions are supposed to evolve within a finite duration. The relaxation matrix ᴦ, a fundamentalquantity of modern theory, then becomes dependent on frequency ω and its spectrum reflects the intracollisionaldynamics [2]. However, the computational complexity makes the ᴦ(ω)-matrix presently unattainable for directfirst-principle calculations and, hence, development of its simplified dynamically-based models has the pivotalrole for further progress.So far, the ᴦ(ω) spectrum has been mimicked by two similar approaches, the frequency-extended, energycorrected sudden approximation (ECSA) [3] and the fast-collision model [4], which tackled the relaxation problemof a linear rotator immersed into a monoatomic gas. Favourably, both models can be applied to arbitrary rotationalspectra, i.e., ones associated with molecular scalars (isotropic polarizability), vectors (dipoles) and tensors(quadrupoles, etc) thus opening the way to multi-property fittings.Here, extensions of these models to an important case of the nonMarkov collisions between two linear rotatorsare reported. These approaches allow straightforward generalizations to similar collisions between any moleculartops whose rotation is substantially slower than the relative translational motion.References[1] P. W. Anderson, "Pressure Broadening in the Microwave and Infra-Red Regions," Phys. Rev. 76, 647 (1949).[2] U. Fano, "Pressure Broadening as a Prototype of Relaxation," Phys. Rev. 131, 259 (1963).[3] J. V. Buldyreva and L. Bonamy, "Non-Markovian Energy-Corrected Sudden Model for the Rototranslational Spectrum of N2," Phys.Rev. A 60, 370 (1999).[4] A. Kouzov, "Rotational relaxation Matrix for Fast Non-Markovian Collisions," Phys. Rev. A 60, 2931 (1999)

M3 - Abstract

T2 - The 17th European Conference on Non-Linear Optical Spectroscopy

Y2 - 8 April 2018 through 11 April 2018

ER -