The hydrogen effect in the electronic structure and bonding of the B2 FeAl alloy with a Fe vacancy

A study of H absorption near a Fe vacancy in a B2 FeAl alloy is performed using density functional calculations. The H locates in an octahedral site (Al capped) where one of the Fe atoms in its base is replaced by a vacancy. The computed Fe–H equilibrium distance is 2.065 Å and the H becomes negatively charged. The overlap population analysis reveals metal–metal bond breaking being the intermetallic bond the more affected.