Ground State Structure of the Metallic Hydrogen

By using Heine-Abarencov pseudopotential method with mono-parameter r_c , the expressions for ground state energy ε(r_s ) , pressure P (r_s), and bulk modulus B(r_s) of metallic hydrogen (fcc, bcc, and hcp structures) are derived. Based on Gibbs free energy function criterion, the calculation shows that cold metallic hydrogen lattice (T = 0K) belongs to hcp structure.