Electronic correlations in uranium hydride UH 5 under pressure.

We report the density functional theory and dynamical mean-field theory (DFT+DMFT) results for the electronic structure of uranium hydride UH5 under pressure, a compound of the uranium-based hydride family some members of which have been predicted to be superconducting. The effective electronic mass enhancement m*/m ~1.4 indicates that the Coulomb correlations have a moderate strength. However, the topology of the Fermi surface changes strongly at the influence of the correlation effects: One hourglass-like pocket running along the Γ-A direction splits into two elliptical pockets centered at the A point. This result shows the possibility of an unconventional pairing mechanism for uranium hydrides in addition to the electron-phonon pairing that was studied in previous investigations.