Seemingly, the diffusion coefficient is delicate to impurities or structural difficulties inside the crystal, but that remains to generally be quantified. For our rough estimates of time at temperature needed to get rid of the hydrogen from our samples, the hydrogen diffusion coefficient selected is given by Belonoshko et al. https://geniusbookmarks.com/story18085532/new-step-by-step-map-for-natural-pukhraj-from-sri-lanka