Studies On The Full Vibrational Energy Spectra And Molecular Dissociation Energies Of Some Heteronuclear Diatomic Electronic States

There are five parts in this dissertation. Part one and part two briefly describe the significance, the progress, the physical models and several physical methods used to study the vibrational energy spectra and the molecular dissociation energies of diatomic molecular electronic states. Part three introduces the algebraic method (AM) and the algebraic energy method (AEM) which are proposed to study the full vibrational energy spectra and the molecular dissociation energies of diatomic molecules. In part four, the AM is applied to obtain full vibrational energies for some electronic states of seven heteronuclear diatomic molecules: NaLi-X~1Σ~+,B~1Π and A~1Σ~+ states, NaK-X~1Σ~+,B~1Π and d~3Π states, NaRb-X~1Σ~+ and a~3Σ~+ states, KH-X~1Σ~+, RbH-X~1Σ~+,DF-X~1Σ~+ and DCl-X~1Σ~+ states. The dissociation energies (DE) of these states are studied using the AEM. The results show that the AM can get accurate vibrational spectroscopic constants and correct full vibrational energy spectrum {E_v} by solving algebraic equation from a known accurate experimental vibrational energy subset without using any mathematical approximations and physical models. These high-lying vibrational energies may be difficult to obtain using modern experimental methods or accurate quantum theoretical methods. Comparing with other experimental or theoretical methods, the AM is a reliable, economical and valid method to obtain full molecular vibrational spectrum, and the AEM is a new physical tool to get accurate molecular dissociation energies, particularly for those diatomic electronic systems whose DE are difficult to accurately obtain using modern experimental technique.