First-principles calculations of hydrogen trapping energy on incoherent interfaces of aluminum alloys

We attempted to calculate the hydrogen trapping energies at the incoherent interfaces of MgZn2 precipitates and Mg2Si crystallites in aluminum alloys from first-principles calculations. Since the unit cell containing the incoherent interface does not satisfy the periodic boundary condition, resulting in a discontinuity of crystal blocks, the hydrogen trapping energy was calculated in a region far from the discontinuity (vacuum) region. We found considerable trapping energies for hydrogen atoms at the incoherent interfaces consisting of assumed atom istic arrangement. W e also conducted preliminary calculations of the reduction i n the cohesive energy by hydrogen trapping on the incoherent interfaces of Mg2Si in the aluminum matrix.