Energy transfer between azulene and krypton: Comparison between experiment and computation

Abstract

Trajectory calculations of collisional energy transfer between excited azulene and Kr are reported, and the results are compared with recent crossed molecular beam experiments by Liu et al. [J. Chem. Phys. 123, 131102 (2005); 124, 054302 (2006)]. Average energy transfer quantities are reported and compared with results obtained before for azulene-Ar collisions. A collisional energy transfer probability density function P(E,E'), calculated at identical initial conditions as experiments, shows a peak at the up-collision branch of P(E,E') at low initial relative translational energy. This peak is absent at higher relative translational energies. There is a supercollision tail at the down-collision side of the probability distribution. Various intermolecular potentials are used and compared. There is broad agreement between experiment and computation, but there are some differences as well.

Equivalence of the Ehrenfest theorem and the fluid-rotor model for mixed quantum/classical theory of collisional energy transfer

“…17,18 On the other hand, for the processes relevant to combustion, 19,20 photochemistry, 21,22 or hyper-thermal phenomena, 23,24 when high energies are involved, the classical-trajectory picture is quite appropriate. [25][26][27][28][29] In between those limits, the quantum mechanical calculations of collisional energy transfer become unaffordable computationally even for the smallest molecular systems (due to a large number of coupled channels and partial waves) while the classical trajectory calculations are not entirely justified and contain serious drawbacks (such as a) Author to whom correspondence should be addressed. Electronic mail:…”

Laguerre polynomial solutions to master equation for vibrational energy relaxation in gases

“…The classical trajectory calculations have confirmed the existence of "supercollisions" at which the abnormally large amount of energy is transferred in a single collision [18][19][20]. The large polyatomic molecules undergo just few (less than 1%) supercollisions during which an energy of about 10 3 − 10 4 cm −1 is transferred to the surrounding cold molecules, whereas the average energy transfer per collision is weak (of order of 10 2 cm −1 ).…”

“…Thus, the present approach reduces the solution of the master equation to the much simpler estimation of G(E i , t i |E, t) from Eqs. (17) and (20). The careful considerations indicate that the case of weak collisions is realized for Z V exceeding Z V ≈10.…”

“…For strong collisions, we recommend to use Eq. (20) instead of (16). The latter should take into account very many terms at short time νt to derive a smooth solution.…”

Determination of the collisional energy transfer distribution responsible for the collision-induced dissociation of NO2 with Ar

“…By ionizing the hot azulene that has had a collision and measuring its velocity distribution utilizing velocity mapped sliced imaging they were able to make a measurement of the shape of the energy transfer function, P(E,E ). Subsequent trajectory calculations of this distribution were disappointingly unable to match the experiment as the calculations predicted only a third of the energy transfer as the experiments measured [41].…”