Hydrogen falls apart under pressure

Solid hydrogen was first predicted around 80 years ago. The theory goes that if you put hydrogen molecules under enough pressure they will solidify. During this process the hydrogen–hydrogen bonds will break and the molecules will fall apart into hydrogen atoms. It is believed the electrons in this solid will flow freely; meaning atomic hydrogen should behave like a metal and conduct electricity. Touted potential uses include as a rocket fuel and in supercomputers.

However, the solid form of hydrogen has so far proved elusive. Claims of success have been made, but later rebuffed. A mixture of molecular and atomic hydrogen layers – called Phase IV – has previously been observed at 2.3 million atmospheres and near room temperature. Now, Eugene Gregoryanz at the University of Edinburgh has produced another mixed form, Phase V, that has a higher proportion of the atomic hydrogen than Phase IV.  The team speculates this Phase V may be a step closer – a precursor even – to solid, atomic hydrogen.