| The spectroscopic properties and transition properties of heavy metal hydride molecules play an important role in physicochemical reactions and the interaction of molecules.Therefore,the structures of electronic states and spectroscopic properties of heavy metal hydride molecules,which is particularly crucial to sufficiently understand and one of the main reasons that attract more and more reseachers to study the theory and experiment of its ground state and excited states.In this paper,the multi-reference configuration interaction plus Davidson correction method(icMRCI+Q)which is used to theoretically study the spectroscopic properties and transition properties of the ground and the low-lying excited states of heavy metal hydride molecules,meanwhile the spin-orbit coupling is taken into account yet.The main research contents can be simply expressed as follows:(1)Using the icMRCI+Q method to calculate the spectroscopic properties of heavy metal hydride molecules.As we can see the five dissociation limits(Hg(~1S_g)+H(~2S_g),Hg(~3P_u)+H(~2S_g),Hg(~1P_u)+H(~2S_g),Hg(~3S_g)+H(~2S_g)and Hg(~1S_g)+H(~2S_g))of HgH molecule correspond to 10?-S electronic states as well as the three dissociatin limits(Ag(~2S_g)+H(~2S_g),Ag(~2P_u)+H(~2S_g)and Ag(~2D_g)+H(~2S_g))of AgH molecule correspond to 12?-S electronic states.The spectroscopic constants of the bound states are obtained by solving the redial Schr?dinger equation and acquired the spectroscopic constants using the Level program.The results of this paper are in good agreement with the earlier experimental results and theoretical values,which shows that our results are certain reliability.At the same time,the analysis of the electronic states show that the heavy metal hydride molecules are extremely obvious multi-reference configuration characteristics.(2)Considering the spin-orbit coupling effect,the interaction of the electronic states of the heavy metal hydride molecules was studied by analyzing the spin-orbit coupling matrix elements of the electronic state and the predissociation mechanism of the HgH molecule was studied.Meanwhile,through the study of the spin-orbit coupling effect,it is also found that for heavy metal hydride molecules,which has great influence on its potential energy curves and spectroscopic properties and is a very significant as well as cannot be ignored problem.After considering the spin-orbit coupling effect of HgH molecule,the seven dissociation limits of?state are generated from five dissociation limits of?-S state,and the three dissociation limits of the AgH molecule are split into five.In this paper,we also analyze the composition of the?states wave function from?-S states of HgH molecule.It is found that there is an avoid accossing between A~2?state and B~2?~+state after considering the spin-orbit coupling effect which because the components have been interchanged near this position.This is also one of the reasons why the spectroscopic properties change greatly after considering the SOC effect.(3)The transition properties of HgH molecule are given in this paper.The transition dipole moments and Franck-Condon factors of several low-excited states to ground states have been calculated,and the corresponding transition radiation lifetimes have been computed.The calculated Franck-Condon factors and radiation lifetimes agree well with the experimental results and theoretical results.(4)There are three properties of the transition of(2)0~+-X0~+of AgH molecule:the intermediate state between the two electronic states which has subtle effect on the transition of the two states;the transition of the two states which has a highly diagonalized Franck-Condon factor;the transition lifetimes of the two transitions are small enough.These properties are vital conditions for molecular cooling.Based on the analysis of these properties,an optical pumping scheme for AgH molecular cooling is proposed in this work. |
PDF Full Text Request