The Establishment Of The Potential Energy Surface Of Ph₂⁺ System And Its Application In Dynamics

As the thermochemical collision reaction of phosphorus compounds is continuously monitored in interstellar clouds.In particular,a large amount of compounds such as HCP,PN and PH3 have been detected in Jupiter's atmosphere,this makes the series of physical and chemical reactions to phosphorus compounds a hot topic of research.As an intermediate product of the reaction of phosphorus compounds,PH₂⁺is of great significance to the study of PH_n⁺?n=0-4?system.However,the potential energy surface is the basis of the dynamic reaction mechanism.PH₂⁺?1¹A??lacks an accurate potential energy surface and related dynamics reports based on the accurate potential energy surface.Therefore,this paper focuses on the detailed modeling and analysis of the two potential energy surfaces of the PH₂⁺system?state 1¹A?and 2¹A??.For the PH₂⁺ground state system,we use the multi-reference configuration interaction?MRCI?method to calculate extensive ab initio energy points based on the aug-cc-pVQZ basis set.Using the many-body expansion theory to construct a full-dimensional global ground state potential energy surface,at the same time,the form of the switching function was introduced to adjust the cross-state between the P⁺?¹D?and P⁺?³P?,the problem of inconsistent dissociation limits of two-body terms P⁺?¹D?+H₂?¹?_g⁺?and PH⁺?X²??+H?²S?was well solved.Comparing the new potential energy surface with the experimental in detail and found to be consistent with the data in other literatures.Based on the new accurate potential energy surface,the quantum time-dependent wave packet method was used to calculate the dynamic behavior,and obtained the integral cross-section?ICS?and reaction probability.The characteristics of the minimum reaction path trajectory and the integral cross-section are combined to predict more quantitative properties of reaction kinetics.these dynamics study can further explain the thermochemical formation of phosphorus-containing molecules in interstellar clouds.We have recalculated the energy points of AVTZ and AVQZ for the PH₂⁺excited state system that is strongly associated with the ground state.The USTE?T,Q?method is used to reasonably extrapolate the energy of the two base groups to the complete basis set?CBS?limit.At this time,the more accurate ab initio energy points were obtained for fitting,use the obtained analytical potential energy equation to draw contour maps under different configurations,and then analysis based on the information of the potential energy surface.Finally,based on the newly constructed global potential energy surface of the excited state,the dynamics detection is performed,and the integral cross-section?ICS?and reaction probability with higher attention are calculated.The obtained results provide support for reaction dynamics and thermochemical reactions of larger phosphorus-containing molecular systems.