English

Effective Coulomb interaction in actinides from linear response approach

Materials Science 2020-01-14 v1

Abstract

The effective on-site Coulomb interaction (Hubbard UU) between 5ff electrons in actinide metals (Th-Cf) is calculated with the framework of density-functional theory (DFT) using linear response approach. The UU values seldom rely on the exchange-correlation functional, spin-orbital coupling, and magnetic states, but depend on the lattice volume and actinide element. Along the actinide series, the Coulomb parameter UU of α\alpha-phase first decreases slowly, followed by a jump in the vicinity of Pu and then a monotonous increase. For light actinides, the lattice volume has a sizeable influence on UU while the localization of 5ff electrons is almost constant. But for transplutonium metals, UU is almost independent of the lattice volume but the electronic localization increases rapidly. The calculated lattice parameters from DFT+UU with the Coulomb parameters as input are in better agreement with the experimental values than those from DFT within local density approximation or Perdew-Burke-Ernzerhof approximation for solids (PBEsol). In particular, the agreement between PBEsol+UU and experiment is remarkable. We show that PBEsol+UU also well reproduce the experimental bulk moduli and the transition from itinerancy to localization of 5ff electrons along the series. Therefore it is concluded that DFT+UU with UU calculated from linear response approach is suitable for a good description of actinide metals.

Keywords

Cite

@article{arxiv.1810.05859,
  title  = {Effective Coulomb interaction in actinides from linear response approach},
  author = {Ruizhi Qiu and Bingyun Ao and Li Huang},
  journal= {arXiv preprint arXiv:1810.05859},
  year   = {2020}
}

Comments

10 pages, 9 figures

R2 v1 2026-06-23T04:38:33.774Z