A Quasi-classical Trajectory Calculation for the Cesium Exchange Reaction of ¹³³CsI (v = 0, j = 0) + ¹³⁵Cs → ¹³³Cs + I¹³⁵Cs

Abstract

To investigate the reaction cross section of the cesium exchange reaction of ¹³³CsI (v = 0, j = 0) + ¹³⁵Cs → ¹³³Cs + I¹³⁵Cs, we performed quasi-classical trajectory calculations. The potential energy surface was constructed at the ab initio MP2/def2-QZVPPD level. The potential energy surface calculated implies that the title reaction is barrierless and that the Cs₂I intermediate, whose two Cs-I bonds are chemically equivalent, is easily formed. The reaction cross sections decrease monotonically with increasing collision energy. The rate constant k (v = 0, j = 0) was estimated to be about 3 × 10^-10 cm³ molecule^-1 s^-1 at temperatures ranging from 500 to 1200 K and a slight negative temperature dependence was observed.