A theoretical study of a H-H pair on the BCC Fe(100) surface

Abstract

Hydrogen adsorption on Fe(100) was analyzed using a semiempirical theoretical method. Calculations were performed using a Fe130 cluster. Adsorption sites for one and two hydrogen atoms on the surface correspond to local energy minima configurations. Changes in the electronic structure of surface Fe atoms were analyzed for the system without hydrogen and with one and two adsorbed hydrogen atoms. Fe atoms close to H weaken their metallic bond. This is due to the formation of H-Fe bonds. Hydrogen influences only its nearest neighbor Fe atoms. The H-H interaction was also analyzed and our results show that H-Fe interaction is much stronger than any possible H-H interaction. No additional decohesion is observed in the Fe-Fe bonds; however, more Fe-Fe bonds are affected.