Abstract: The adsorption of N2 molecule on the UO(100) surface was studied with periodic slab model by VWN-BP approach of GGA within the framework of density functional theory (DFT). The results of geometry optimization indicated that the most stable structure of adsorption was N2 adsorbed parallelly on the hollow site with an adsorption energy of 79.0 kJ·mol -1. The analysis of Mulliken population and density of states indicated that 2π antibonding orbitals of N2 molecules got electrons from d and f orbitals in uranium. The vibration wave number of N—N range from 1770 to 2143 cm-1. Complete linear synchronous transit (LST) and quadratic synchronous transit (QST) were used to search the transition state for dissociation reaction. The predicted lowest energy barrier was 266.9 kJ·mol-1.

Key words: Density functional theory, N2, Adsorption, Dissociation, UO