The Study Of Global Potential Energy Surfaces And Dynamic Of Free Radical AlH₂ Molecular And Its Positive Ion

The aluminum is not only the most abundant metal element in the crustal layer,but also produces a large number of compounds due to its active chemical properties.As a typical hybrid molecule,aluminum-hydrogen compounds have good prospects in the fields of solid fuel and hydrogen storage materials.In addition,because of its inflammable,explosive and corrosion,also caused great trouble to daily life.In recent years,it has been found that the insertion of metal into hydrogen molecules at low temperature has potential scientific significance.In this paper,we explore the reaction process and molecular characteristics of the first three electronic states of free radicalsAlH₂ and the ground state ofAlH₂from the perspective of global potential energy surface,and study the dynamics on the new potential energy surfaces of the four electronic states.In this paper,the ground state ofAlH₂ is discussed firstly.In the first place,thousands of ab initio potential energy points are obtained from the molpro quantum chemical computing software package based on the complete active space self-consistent field theory,the multi-reference configuration interaction method and the Dunning correlation uniformly polarized valence layer basis sets aug-cc-pVXZ?X=Q,5?.Then the energy points are further processed by base basis set extrapolation to obtain more accurate energies data.Then the global potential energy surface of theAlH₂?¹ A?is obtained by using the many body expansion theory,and the spectral parameters and reaction mechanism of the AlH₂?¹A?are obtained based on the information of the potential energy surface.Finally,the quasi-classical trajectory method and quantum time-dependent wave packet method are used to study the dynamic feature based on the new potential energy surface respectively,the results are in good agreement with the experimental results and better than those of previous researcher's theoretical result.The second study is to explore insert reaction,energy lowest path,state-state reaction mechanism and so on by fitting the potential energy surfaces of the first three electronic states ofAlH₂.The method used is basically the same as that used by the ground state ofAlH₂,except that the basis sets used are aug-cc-pVXZ?X=T,Q?and the state-averaged calculation.Finally,we also calculate the molecular reaction dynamics of the three electronic states,which fill in the blank about this aspect.