Electronic structure of PrBa2Cu3O7 after high-pressure compression from first principles

The influence of the high-pressure compression (P ≅ 9 GPa) on the electronic band structure, charge distribution and magnetic moments of the fully oxygenated, ideally stoichiometric PrBa2Cu3O7 system was investigated. The following changes were observed as a result of the simulated compression: (i) the reduced total density of states (DOS) at the Fermi level EF, (ii) the increased difference between spin-up and spin-down total DOS in the nearest vicinity of EF (spin splitting), (iii) the lowered occupation of Pr 4f band crossing EF, (iv) the stronger localization of partial charges in all atomic spheres, (v) the reduced amount of holes in the CuO2 planes and (vi) the enhanced magnetic moments in the system, especially in the cupric-oxide planes. Our results indicate the possibility of negative pressure effect on the superconductivity in the optimally doped PrBa2Cu3O7 system at the sufficiently high hydrostatic pressure.