Why does magnesium-based solid hydrogen storage have a large hydrogen storage capacity?

There are many gaps in the structure. Magnesium-based solid-state hydrogen storage refers to storing hydrogen into magnesium materials by physical or chemical means to realize long-term stable storage and release of hydrogen. The reason why magnesium-based solid-state hydrogen storage has a large amount of hydrogen storage is that there are many gaps in the lattice structure of magnesium metal, so that hydrogen can be closely embedded in it.