  Coincidence Site Lattice (CSL) grain boundaries (GBs) are believed to be
low-energy, resistant to intergranular fracture, as well as to hydrogen
embrittlement. Nevertheless, the behavior of CSL-GBs are generally confused
with their angular deviations. In the current study, the effect of angular
deviation from the perfect sigma3 (111) [1-10] GBs in Alpha-iron on the
hydrogen diffusion and the susceptibility of the GB to hydrogen embrittlement
is investigated through molecular static and dynamics simulations. By utilizing
Rice-Wang model it is shown that the ideal GB shows the highest resistance to
decohesion below the hydrogen saturation limit. Finally, the hydrogen
diffusivity along the ideal GB is observed to be the highest.
