[nulltxt]

H4 Seems to exist here https://en.m.wikipedia.org/wiki/Isotopes_of_hydrogen.

[powera]

Nope. That is discussing "an atom of hydrogen with 1 proton and 3 neutrons". Which kind-of exists, but is too unstable to be meaningful.

The press release says it is a molecule of 4 hydrogen atoms. Neither the press release nor Wikipedia have any further thoughts as to how this is possible.

[comicjk]

I have long harbored an ambition of creating a Journal Of Implausible Chemistry, for the publication of research on hydrogen chains and other molecules cruelly disallowed by our impoverished reality.