Stability of hydrogen in tungsten with carbon impurity: a first-principles study
带有碳杂质的钨中氢稳定性的第一性原理研究

Stability of hydrogen（H） in tungsten（W） with carbon（C） impurity is investigated by using the first-principles method.In intrinsic W,C exhibits a week attractive interaction with H at a distance of 2.5A,and it is the most stable site of H in the bulk W with C.In the presence of the monovacancy in W,H prefers to bind onto an isosurface of the same charge density of 0.10 A-3,due to the existence of C.Our research finds that the monovacancy in W can contain only ten H atoms and H molecule cannot be formed in comparison with the result without C,suggesting a strong effect of C on H stability in W.When two C atoms exit in the vacancy,the charge density of the isosurface that H binds onto is 0.13 A-3.