The much more important consideration is that metallic hydrogen may prove to be stable (although its state will, of course, be metastable) even under zero or comparatively low pressure. ... It is possible, however, that the liquid state can exist at pressures exceeding the equilibrium pressure.

Is metallic hydrogen stable at room temperature?

As a synthetic material, metallic hydrogen would also have endless applications. First off, it is believed to have superconducting properties at room temperature, and is meta-stable (meaning that it will retain its solidity once it returns to normal pressure).

How strong is metallic hydrogen?

Hydrogen under pressure

Since the first work by Wigner and Huntington, the more modern theoretical calculations point towards higher but nonetheless potentially achievable metallization pressures of around 400 GPa (3,900,000 atm; 58,000,000 psi).