Using and validation of the DFT method for oxygen adsorbed on the iron (100) surface

Electronic and structural properties of atomic oxygen adsorbed on the iron (100) surface are examined using density functional theory calculations. The oxygen adsorbed on the iron (100) surface is investigated at the three adsorption sites top, bridge and hollow sites respectively. Adsorption energy, work function and surface geometries were calculated, the hollow site was found to be the most stable adsorption site, which is in agreement with the experiment. In addition, the difference charge density of the different adsorption system was calculated to analyse the interaction and bonding properties between Fe and O. It can be found out that the charge redistribution was related to the geometry relaxation. The calculated results are compared with the experimental and other theoretical results.