First-principles calculation of structural, electronic, and superconducting properties of PuH_x, 6 x 10

Plutonium polyhydrides are fascinating systems not only because plutonium is an important element in nuclear industry with complicated 5f electron behaviors, but also because metal polyhydrides are potential superconducting materials. Here, we have performed first-principles calculations, which adopts the projectedaugmented wave (PAW) approach with the Perdew-Burke-Ernzerhof (PBE)-type functional including an onsite Hubbard U correction, to investigate the structural, electronic, and superconducting properties of hydrogen-rich PuHx (6 <= x <= 10) in clathrate structure under high pressures up to 350 GPa. All systems are found to be metallic with occupied states near the Fermi level contributed mainly by Pu-5f electrons. The highest superconducting transition temperature T-c of PuHx is only 26.4 K (PuH10 under 300 GPa), and other predicted Tc are less than 1 K, showing that the f electrons in plutonium are harmful to the superconductivity in plutonium polyhydrides.