[lemma=storage] [tag=NNS] [!tag=IN] [lemma=pure] [□=□]
[lemma=storage] [tag=NNS] [!tag=IN] [lemma=pure] [tag=□]
[lemma=storage] [tag=NNS] [!tag=IN] [lemma=pure] [lemma=□]
Of potential practical hydrogen storage materials , pure Mg would be best from the standpoint of hydrogen capacity per unit mass .