We have studied the adsorption, vibration, and diffusion of N atoms on Ru(0001), (10 (1) over bar0), (1120) and (11 (2) over bar1) surfaces by means of the 5-parameter Morse potential (5-MP) of interaction between atomic nitrogen and a metal surface. The adsorption sites, adsorption geometry, binding energy and eigenvibration of atomic nitrogen on the different ruthenium surfaces are calculated. It is shown that atomic nitrogen always preferably occupies the high coordination sites on Ru surfaces. The 4-fold site is the preferable adsorption site for atomic nitrogen on both open Ru(11 (2) over bar0) and (11 (2) over bar1) surfaces while 3-fold site is the most stable adsorption site for atomic nitrogen on both Ru(0001) and (10 (1) over bar0) surfaces. Moreover, we find the lowest energy pathway of diffusion and diffusion barriers of atomic nitrogen on the surfaces. (C) 2008 Elsevier B.V. All rights reserved.