The electronic structure and bonding of a H-H pair in the vicinity of a bcc bulk vacancy

ALFREDO JUAN; CAROLINA PISTONESI; ALEJANDRO J. GARCÍA; GRACIELA BRIZUELA

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2003 vol. 28 p. 995 - 1004

0360-3199

The H–Fe interaction near a bcc Fe vacancy is analysed using a semi-empirical theoretical method. Calculations were performed using a Fe86 cluster with a vacancy. Hydrogen atoms are positioned in their local energy minima con9gurations. Changes in the electronic structure of Fe atoms near a vacancy were analysed for the system without H, with one H and with two H atoms. Fe atoms surrounding the vacancy weaken their bond when hydrogen is present. This is due to the formation of H–Fe bonds. Hydrogen in:uences only its nearest-neighbour Fe atoms. The H–H interaction was also analysed. For H–H distance of 0:82 ;A an H–H association is formed, while H–Fe interaction and Fe–Fe weakening is markedly reduced, when compared with other H–H interactions. ? 2003 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.