Maybe of interest

https://phys.org/news/2019-07-…d-interaction-metals.html

Scientists create predictive model for hydrogen-nanovoid interaction in metals

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Quote

In the end, however, they discovered that hydrogen trapping behavior in nanovoids—although apparently complicated—actually follows simple rules.

First, individual hydrogen atoms are adsorbed, in a mutually exclusive way, by the inner surface of nanovoids with distinct energy levels. Second, after a period of surface adsorption, hydrogen is pushed—due to limited space—to the nanovoid core where molecular hydrogen gas then accumulates.

Following these rules, the team created a model that accurately predicts properties of hydrogen nanobubbles and accords well with recent experimental observations.