The influence of Pauli blocking effects on the properties of dense hydrogen

We investigate the effects of Pauli blocking on the properties of hydrogen at high pressures, where recent experiments have shown a transition from insulating behavior to metal-like conductivity. Since the Pauli principle prevents multiple occupation of electron states (Pauli blocking), atomic states disintegrate subsequently at high densities (Mott effect). We calculate the energy shifts due to Pauli blocking and discuss the Mott effect solving an effective Schrödinger equation for strongly correlated systems. The ionization equilibrium is treated on the basis of a chemical approach. Results for the ionization equilibrium and the pressure in the region 4 000 K < T < 20 000 K are presented. We show that the transition to a highly conducting state is softer than found in earlier work. A first order phase transition is observed at T < 6 450 K, but a diffuse transition appears still up to 20 000 K.