A theoretical study of the structures and chemical bonds of neptunium (III) molecules by a density functional method
Key Laboratory of Atomic and Molecular Physics
& Functional Materials, College of Physics and Electronic Engineering,
Northwest Normal University, Lanzhou
730070, Gansu Province, P.R.
Received in final form: 30 May 2014
Published online: 21 October 2014
In this paper, equilibrium structures and chemical bond characteristics of neptunium trihalide molecules NpX3 (X = F, Cl, Br and I) have been investigated by using density functional theory (DFT). The influences of the size of the relativistic effective core potential (RECP) have been examined on the molecular structures. The chemical bond characteristics have also been systematically studied by calculating the density of states (DOS), bond length differences and electronic charge distributions. We have determined that the chemical bonds are mainly ionic in those molecules, and the covalency is enhancing while ionicity decreases from NpF3 to NpI3. The calculated bond energies show that the interaction strength in NpX3 molecules becomes weaker as the halogen atoms becoming heavier.
Key words: Molecular Physics and Chemical Physics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2014