Mutual influence of hydrogen and vacancies in $\alpha$-zirconium on the energy of their interaction with metal

We presents a first-principles investigation on the interaction energy of hydrogen and vacancies with $\alpha$-zirconium. It is established that the presence of vacancies in zirconium increases the hydrogen–metal binding energy; the presence of hydrogen in the zirconium lattice reduces the vacancy formation energy. It is shown that hydrogen and vacancies in zirconium form complexes that considerably distort the metal lattice. The increase in the covalency degree of the metal–metal and hydrogen–metal bounds is observed in the vicinity of these complexes.