Theoretical Studies On The R-branch Transition Spectra Of High-lying Rovibronic States Of Diatomic Molecules

A new analytical formula is derived from conventional expression of R-branch transitional energies for diatomic molecule based on the difference converging method(DCM)that was established in our previous work.Using the new formula,only a set of 11 known R-branch experimental transition spectral lines needed to predict correct high-lying transitional spectra that may not be available experimentally.In this work,the R-branch spectral data of(0,0)band in the A30+?X10+ transitional system of NaAs molecule and the A20+?X10+,A20+?X21 transitional system of BiLi molecule are studied.At the same time,a new method for predicting the error accuracy between experimental and theoretical values is proposed,a series of analysis and discussions in this paper,the results show that:(1)For the transition band of R-branch system in the molecular system,the DCM method can select 11 transition lines which have the least error and best characterization of the physical properties of the whole transition band from a limited set of experimental transition line data.Based on computation by new formula.The results not only obtain some unknown low-lying transitional spectra,but also correctly predict the high excited states transitional lines including rotational quantum number up to J=80.(2)The new formula can accurately predict the transition spectra of highly excited vibrational and rotational states without using any vibrational and rotational spectral constants of molecules.DCM method provides an effective and simple new way to study the R-branch transition spectra of diatomic molecules.(3)By using the new method,the prediction error accuracy ?? is given quantitatively.The relevant data provide an important theoretical support for the reliability of the prediction of high excited state transition spectral line data.This paper is divided into five chapters.The first chapter describes the significance,progress,purpose and content of molecular spectroscopy;the second chapter describes the theoretical basis and the experimental and theoretical methods for the study of binuclear molecular transition lines;the third chapter derives in detail a new analytical table for calculating the transition lines of Binuclear R-line system based on the idea of differentiation.In the fourth chapter,the R-line transition spectra of the highly excited vibrational and rotational states in the transition bands of partial electronic states of NaAs and BiLi molecules are studied by using the new formulas.The fifth chapter summarizes this paper.