A quasiclassical trajectory calculation to compute the reaction cross section and thermal rate constant for the cesium exchange reaction 133CsI + 135Cs → 133Cs + I135Cs

Publication date: Available online 11 January 2019Source: Computational and Theoretical ChemistryAuthor(s): Takanori Kobayashi, Leo Matsuoka, Keiichi YokoyamaAbstractTo compute the reaction cross section and the thermal rate constant of the cesium exchange reaction 133CsI + 135Cs → 133Cs + I135Cs in the temperature range 500–1,500 K, we performed a quasiclassical trajectory calculation using a potential energy surface developed from an ab initio calculation at the MP2/def2-QZVPPD level. The state-specific cross sections and their dependences on the initial vibrational and rotational quantum numbers of 133CsI (v and j, respectively) were analyzed. The v-j thermally averaged cross section and its dependence on the collision energy was also analyzed. The thermally averaged rate constant is above 3.6 × 10−10 cm3 molecule−1 s−1 and slightly increases with temperature within the investigated temperature range. The positive temperature dependence might indicate that the title reaction is controlled by long-range dispersion forces. The subsequent dissociation step might also contribute to the positive temperature dependence.Graphical abstract

Source: Computational and Theoretical Chemistry - January 11, 2019 Category: Chemistry Source Type: research