Construction Of Potential Energy Surface Of High-precision Full-dimensional Global Bh⁺₂ System

Boron is one of the most interesting elements in the periodic table.The theoretical and experimental studies of boron ion clusters and boron-rich materials are of great interest.Boron has important application value in engineering and can be used as rocket propellant and hydrogen storage material.Boron has only five extranuclear electrons,which seems to have a simple structure,but is very complicated to study.Only the multiplicity of the base electronic states of B₂molecule has been studied for a long time.Therefore,there are very few structural data of BH₂⁺,so it is necessary to construct the full-dimensional global potential energy surface of BH₂⁺system,which can play an important reference role in the study of boron-rich materials.In this article,two potential energy surfaces of ground state and excited state are fitted respectively.For the ground state BH₂⁺system,a large number of ab initio energy points are calculated at the multiple reference configuration interaction(MRCI)level by aug-cc-PV(Q,5)Z basis set and extrapolated to the complete basis set limit.The full-dimensional global potential energy surface of the ground state BH₂⁺is constructed by many-body expansion.To ensure the consistency of the dissociation limits of B⁺(~3P)+H₂(X~1?_g⁺)and BH⁺(X~2?⁺)+H(~2S),a switching function are designed to simulate the transition from B⁺(~3P)to B⁺(~1S).The topographic features of the new global potential energy surface are discussed in detail and agree well with the previous theoretical results.The integral cross sections of H₂(X~1?_g⁺)(v=0,j=0)?BH⁺(X~2?⁺)+H(~2S)reactions are calculated using quasi-classical trajectory method,which provides support for the reliability of BH₂⁺potential energy surface.For the excited state BH₂⁺system with higher energy,we adopt the multi-reference configuration interaction theory with the self-consistent field of fully active space as the reference wave function,and use USTE(Q,5)method to extrapolate the calculated aug-cc-p VXZ(X=Q,5)ab initio energy points to the complete basis set(CBS)limit.A full-dimensional global excited BH₂⁺potential energy surface is constructed by using many-body expansion form.The global minimum value of excited state BH₂⁺potential energy surface is given theoretically for the first time without reference to experimental values.Finally,the dynamic test of BH₂⁺system are carried out,and the reaction probability are analyzed by using the quantum time-dependent wave packet method,which make our study on BH₂⁺system more thorough,and the data obtained can provide theoretical support for other researches on BH⁺.