Search of hydrogen transition states on a-Fe: the monomer adapted to first principles calculations

V. P. RAMUNNI, R.C. PASIANOT Y P. BRUZZONI

Tandar CNEA - Buenos Aires

Conferencia; At de Frontiers of Condensed Matter IV: Current Trends and Novel Materials; 2008

CNEA

In the context of the density functional theory(DFT), we use the ab-initio electronic structure code, SIESTA, coupled to an economic technique to find activated states (or migration barriers), in order to study atomic defects diffusion through the crystal lattice: The Monomer method [V.P. Ramunni, Phys. Rev. B 74, 054113 (2006)]. We test our technique calculating the activated transition states of interstitial hydrogen (H) between two sites of high symmetry, tetrahedral and octahedral, in the bcc and fcc phases of Fe. The results are discussed in the context of experimental data and other available models.