Potential energy curve and spectroscopic parameters of multi-charged LiF molecule

Abstract

In the study of the special properties of molecules, diatomic molecules are vital. Three quantum mechanics methods were used to calculate the optimised structure and total electronic energy of the LiF molecule; namely, the Hartree–Fock (HF), density functional theory (DFT), and coupled cluster singles and doubles (and triples) (CCSD(T)) methods. The optimised structure properties, such as diploe moment, spectroscopic constants, and vibrational frequency, were calculated, as well as the potential energy curves. This study found that the negative LiF molecule is more stable than the neutral LiF molecule, and that the positive LiF molecule is unstable. These results were supported by the values of vibrational frequency and spectroscopic constants of LiF.