The Investigation For Reaction Systems N+H₂ And Al+H₂ With Time-dependent Wave Packet Theory

Molecular reaction kinetics is a subject that investigates the elementary reactions and the related processes of chemical rate in physics at the molecular level including movement of molecules and intermolecular collisions.These two relationships together present the"micro"foundation of all macroscopic rate phenomena.To understand the dynamics of a system at the molecular level is the key to explain the"macro"dynamics of the entire system.In this paper,we researched the kinetic behavior of the reaction systems N+H₂ and Al+H₂ in detail with the time-dependent quantum wave packet method.First of all,based on the globally accurate potential energy surface of the first excited state of NH₂（1²A′）constructed by Li et al.,using the quantum time-dependent wave packet method,we calculated the total angular momentum J=0,8,16,24,30and 45 reaction probability.Then,the effect of Coriolis coupling on the reaction N（²D）+H₂（X¹Σ_g⁺）was investigated.Because of the existence of the deep potential well in the reaction process,the reaction probability calculated by Coriolis coupling and centrifugal sudden approximation has resonance structure.In addition,the resonance characteristic of Coriolis coupling is weaker than that of centrifugal sudden approximation since different K states are coupled in the Coriolis coupling calculation.Compared the integral cross section calculated by the Coriolis coupling with centrifugal sudden approximation,it is observed that the former has a great influence on the response and cannot be ignored in calculation.Finally,we make a comparison among the j-dependent Integral cross section at the whole collision energy range,and find that N₂ rotational excitation promotes the reaction.Secondly,using the time-dependent wave packet method,we first calculate the probabilities under the total angular momentum J=0,10,20,30,40,50,60 and 70 on the global precise potential energy surface of Al H₂（X²A₁）constructed by Wang et al.Then,the influence of Coriolis coupling on the reaction Al（²P）+H₂（X¹Σ_g⁺）was studied.Due to the existence of deep potential wells in the reaction process,all of the reaction probabilities calculated by Coriolis coupling and centrifugal approximation have a resonance structure.Moreover,due to the coupling of different K states in the calculation process,the vibration characteristics of Coriolis coupling are weaker than the centrifugal sudden approximation.Comparing the integral cross section calculated by Coriolis coupling and centrifugal approximation,it is found that Coriolis coupling has a great influence on the reaction,which cannot be ignored in this calculation.Finally,we compared the integral cross section of j=0,1,2,3,4,5,6 and v=0,1,2,3,4,5 in the entire collision energy range,and found that the H₂ rotation excitation and Vibration excitation will promote the progress of the reaction.But compared to rotational excitation,vibration excitation can promote the reaction more,because the potential barrier on the potential energy surface is in the exit valley,which is a late barrier.For the late barrier,the vibrational energy can promote the reaction even more.