Effective Coulomb interaction in actinides from linear response approach

Abstract

The effective on-site Coulomb interaction (Hubbard U) between 5f electrons in actinide metals (Th-Cf) is calculated with the framework of density-functional theory (DFT) using linear response approach. The value of Hubbard U seldom relies on the exchange-correlation functional, spin-orbital coupling, and magnetic state, but depends on the neighbor distance and actinide element. In particular, a pronounced dependence of Hubbard U on the Wyckoff position is shown for β-U. We find an abrupt increase of Hubbard U from α-Pu to α-Am along the actinide series, which is similar to that of atomic volume. Within local-density approximation or generalized gradient approximation of Perdew-Burke-Ernzerhof revised for solids, the calculated structural properties from DFT + U with U from linear response calculation are in good agreement with the experimental data.