70 years of Landau–Teller theory for collisional energy transfer. Semiclassical three-dimensional generalizations of the classical collinear model

Nikitin, E. E.; Troe, J.

doi:10.1039/b715095d

Cited by 50 publications

(44 citation statements)

References 92 publications

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“…We account for processes (R14) and (R15) assuming that their rate coefficients are related to those for υ = 1 according to the Landau-Teller theory as k 14 (υ) = υk 3 and k 15 (υ) = υk 4 . 63 The addition of these processes does not have significant effect to the model output and requires no additional correction to the value of k 2,fit .…”

Section: Corrections To the Preliminary Values Of The O 2 (X 3 −mentioning

confidence: 99%

Collisional relaxation of O2($X^3\Sigma _g^ -$X3Σg−, υ = 1) and O2(a1Δg, υ = 1) by atmospherically relevant species

Pejaković

Campbell

Kalogerakis

et al. 2011

The Journal of Chemical Physics

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Laboratory measurements are reported of the rate coefficient for collisional removal of O(2)(X(3)Σ(g)(-), υ = 1) by O((3)P), and the rate coefficients for removal of O(2)(a(1)Δ(g), υ = 1) by O(2), CO(2), and O((3)P). A two-laser method is employed, in which the pulsed output of the first laser at 285 nm photolyzes ozone to produce oxygen atoms and O(2)(a(1)Δ(g), υ = 1), and the output of the second laser detects O(2)(a(1)Δ(g), υ = 1) via resonance-enhanced multiphoton ionization. The kinetics of O(2)(X(3)Σ(g)(-), υ = 1) + O((3)P) relaxation is inferred from the temporal evolution of O(2)(a(1)Δ(g), υ = 1), an approach enabled by the rapid collision-induced equilibration of the O(2)(X(3)Σ(g)(-), υ = 1) and O(2)(a(1)Δ(g), υ = 1) populations in the system. The measured O(2)(X(3)Σ(g)(-), υ = 1) + O((3)P) rate coefficient is (2.9 ± 0.6) × 10(-12) cm(3) s(-1) at 295 K and (3.4 ± 0.6) × 10(-12) cm(3) s(-1) at 240 K. These values are consistent with the previously reported result of (3.2 ± 1.0) × 10(-12) cm(3) s(-1), which was obtained at 315 K using a different experimental approach [K. S. Kalogerakis, R. A. Copeland, and T. G. Slanger, J. Chem. Phys. 123, 194303 (2005)]. For removal of O(2)(a(1)Δ(g), υ = 1) by O((3)P), the upper limits for the rate coefficient are 4 × 10(-13) cm(3) s(-1) at 295 K and 6 × 10(-13) cm(3) s(-1) at 240 K. The rate coefficient for removal of O(2)(a(1)Δ(g), υ = 1) by O(2) is (5.6 ± 0.6) × 10(-11) cm(3) s(-1) at 295 K and (5.9 ± 0.5) × 10(-11) cm(3) s(-1) at 240 K. The O(2)(a(1)Δ(g), υ = 1) + CO(2) rate coefficient is (1.5 ± 0.2) × 10(-14) cm(3) s(-1) at 295 K and (1.2 ± 0.1) × 10(-14) cm(3) s(-1) at 240 K. The implications of the measured rate coefficients for modeling of atmospheric emissions are discussed.

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Section: Corrections To the Preliminary Values Of The O 2 (X 3 −mentioning

confidence: 99%

Collisional relaxation of O2($X^3\Sigma _g^ -$X3Σg−, υ = 1) and O2(a1Δg, υ = 1) by atmospherically relevant species

Pejaković

Campbell

Kalogerakis

et al. 2011

The Journal of Chemical Physics

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show abstract

“…follows an m À2 r À3 dependence, where m is the dipole moment of the optical transition (Massey, Burhop, & Gilbody, 1974;Nikitin, 1974). Nikitin and Troe (2008) have recently reviewed the basics of Landau-Teller theory. Since the probability of forming an excited state in the departing ion is a function of P(1 À P), it is clear that there will be a set of conditions that represents a maximum in this probablility.…”

Section: Mechanisms Of Collisional Activationmentioning

confidence: 99%

The mechanisms of collisional activation of ions in mass spectrometry

Mayer

Poon

2009

Mass Spectrometry Reviews

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This article is a review of the mechanisms responsible for collisional activation of ions in mass spectrometers. Part I gives a general introduction to the processes occurring when a projectile ion and neutral target collide. The theoretical background to the physical phenomena of curve-crossing excitation (for electronic and vibrational excitation), impulsive collisions (for direct translational to vibrational energy transfer), and the formation of long-lived collision intermediates is presented. Part II highlights the experimental and computational investigations that have been made into collisional activation for four experimental conditions: high (>100 eV) and intermediate (1-100 eV) center-of-mass collision energies, slow heating collisions (multiple low-energy collisions) and collisions with surfaces. The emphasis in this section is on the derived post-collision internal energy distributions that have been found to be typical for projectile ions undergoing collisions in these regimes.

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“…First, the Landau-Teller (LT) model is used to simplify the first two terms. The LT equation can only be derived from the master equation under certain assumptions 37,38 , such as mono-quantum transitions. However, use of the LT model is common in CFD codes used for flows in thermal nonequilibrium, and there is evidence that vibrational energy relaxation time constants, determined both experimentally and computationally, can be accurately fit with the LT model 1,2,16 .…”

Section: Kinetic To Continuum Frameworkmentioning

confidence: 99%

Consistent Kinetic And Continuum Dissociation Models For High-Temperature Air

Singh

Schwartzentruber

2020

AIAA Scitech 2020 Forum

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In this article, we propose a generalized non-equilibrium chemical kinetics model from ab initio simulation data obtained using accurate potential energy surfaces developed recently for the purpose of studying high-temperature air chemistry. First, we present a simple cross-section model for dissociation that captures recent ab initio data accurately. The cross-section model is analytically integrated over Boltzmann distributions and general non-Boltzmann distributions to derive general non-equilibrium dissociation model. The general non-Boltzmann model systematically incorporates key physics such as dependence on translational energy, rotational energy, vibrational energy, internal energy, centrifugal barrier and non-Boltzmann effects such as overpopulation and depletion of high energy states. The model is shown to reproduce the rates from QCT for Boltzmann distributions of internal energy states. Reduced rates in non-equilibrium steady state due to depletion of high internal energy states are also predicted well by the model. Furthermore, the model predicts the enhanced rates as observed due to significant overpopulation of high vibrational states relative to Boltzmann distributions while the gas is in non-equilibrium in the transient phase. The model provides a computationally inexpensive way of incorporating non-equilibrium chemistry without incurring additional cost in the existing computational tools. Further comparisons of the model are carried out in another article, where simplifications to the model are proposed based on the results.

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70 years of Landau–Teller theory for collisional energy transfer. Semiclassical three-dimensional generalizations of the classical collinear model

Cited by 50 publications

References 92 publications

Collisional relaxation of O2($X^3\Sigma _g^ -$X3Σg−, υ = 1) and O2(a1Δg, υ = 1) by atmospherically relevant species

Collisional relaxation of O2($X^3\Sigma _g^ -$X3Σg−, υ = 1) and O2(a1Δg, υ = 1) by atmospherically relevant species

The mechanisms of collisional activation of ions in mass spectrometry

Consistent Kinetic And Continuum Dissociation Models For High-Temperature Air

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