Apparently, the diffusion coefficient is delicate to impurities or structural difficulties in the crystal, but that remains to be quantified. For our tough estimates of time at temperature needed to clear away the hydrogen from our samples, the hydrogen diffusion coefficient preferred is usually that presented by Belonoshko et al. https://crossbookmark.com/story17974437/the-smart-trick-of-buy-sri-lanka-pukhraj-in-india-that-nobody-is-discussing