Study On Molecular Reaction Dynamics Of H₂X⁺ System Based On The New Potential Energy Surface

The reaction between radical reaction of triatomic systems plays an important role in atmospheric chemistry.This type of reaction has attracted widespread attention and research due to its influence in the chemistry of interstellar clouds.When dealing with the dynamics of triatomic and polyatomic reaction systems,researchers mostly choose the Time Dependent Wave Packet Method（TDWP）.Because the TDWP method has both the intuitiveness of classical mechanics and the precision of quantum mechanics.In order to use TDWP method,we first need to select the appropriate coordinate system and basis function,construct the initial wave packet of the system,according to the characteristics of the system and the required accuracy of the calculation.Then we solve the time-dependent Schr（?）dinger equation of the system and use a suitable propagation method to propagate the wave packet.Finally,we calculate the required physical quantity by analyzing the wave function obtained after propagation.In this dissertation,based on the latest electronic ground state H₂S⁺（X⁴A"）potential energy surface（PES）constructed by Song Yuzhi et al.,we studied the reaction dynamics of the S⁺+H₂reaction.We used the TDWP method to calculate the reaction probability and integrated cross section.The effect of vibration excitation and rotation excitation were also discussed.In order to choose the optimal the Coriolis coupling（Coriolis Coupling,CC）terms N_K,we first investigated the N_Kcorrelation of the reaction,and then calculated the reaction probabilities of different angular momentum J.By analyzing the attributes of the H₂S⁺（X ⁴A"）PES,it is obtained that there is a potential barrier on this PES.We also obtained that the reaction probability can be enhanced by the vibrational and rotational excitation.Thus,it can be concluded that the reaction is an endothermic reaction.We have also studied the effect of the CC effect on the reaction system.This effect is of great significance in some reactions.However,this effect has little effect on some reactions.If the CC effect is considered in the calculation,it will takes much more computational time.Therefore,whether to consider this effect is necessary to study in the reaction dynamics.Through calculation and analysis,we can concluded that this effect has little influence on the S⁺+H₂reaction,thus we can ignore this effect without loosing the accuracy of the reaction.The reaction dynamics of H+OH⁺is also studied.Based on the PES constructed by Paniagua et al.,the CC effect on the reaction is studied.In order to illustrate the effect on the reaction,the obtained reaction probability and integrated reaction cross section including CC were compared with the results without considering this effect.The results show that the CC effect has important influence on the H+OH⁺system.In order to ensure the accuracy of the calculation,the CC effect needs to be considered for the H+OH⁺reaction.The structure of this dissertation is as follows:First,we briefly introduce the basic theoretical foundation of PES and molecular reaction dynamics.The reaction dynamics of the S⁺+H₂and H+OH⁺reactions are then studied in details.Most importantly,the CC effect were investigated in details.Finally,the summary and future research are given.