The electronic structure and bonding of an hydrogen pair near a FCC Fe stacking fault

A. JUAN; L. MORO; G. BRIZUELA; M. E. PRONSATO

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

Elsevier Science Ltd.

Año: 2002 vol. 27 p. 333 - 338

0360-3199

The bonding of H to Fe is analyzed using qualitative electronic calculations in the framework of the atom superposition and electron delocalization orbital cluster method (ASED–MO). Upon introduction of a stacking fault in FCC Fe, the changes in the electronic structure are studied when a pair of hydrogen atoms are located near the fault. A cluster of 180 metallic atoms distributed in 7ve layers represents the solid. The interstitial H atoms are positioned in accordance with previous studies. The Fe–H interaction decreases the Fe–Fe bond strength and the H e8ect is limited to the 7rst Fe neighbor. An analysis of the orbital interaction reveals that the Fe–H bonding involves mainly the Fe 4s and H 1s orbitals. The orbital population analysis reveals some H–H association, which is more important than that obtained in dislocated Fe. A comparison is given with H pairs located near BCC Fe dislocations or vacancies.