Metallic hydrogen with a strong electron-phonon coupling at a pressure of 300–500 GPa

Atomic metallic hydrogen, which has a lattice with the $FDDD$ unit cell symmetry, has been shown to be a stable phase at a hydrostatic pressure of 350–500 GPa. The found structure has a phonon spectrum which is stable with respect to decay. The structural, electronic, phonon, etc., characteristics of normal metallic phases of hydrogen at a pressure of 350-500 GPa have been ab initio calculated.