The effective on-site Coulomb interaction (Hubbard U) between localized \textit{d} electrons in 3\textit{d}, 4\textit{d}, and 5\textit{d} transition metals is calculated employing a new parameter-free realization of the constrained random-phase approximation using Wannier functions within the full-potential linearized augmented-plane-wave method. The U values lie between 1.5 and 5.7 eV and depend on the crystal structure, spin polarization, \textit{d} electron number, and \textit{d} orbital filling. On the basis of the calculated U parameters, we discuss the strength of the electronic correlations and the instability of the paramagnetic state towards the ferromagnetic one for 3\textit{d} metals.
@article{arxiv.1103.5593,
title = {Effective Coulomb interaction in transition metals from constrained random-phase approximation},
author = {Ersoy Sasioglu and Christoph Friedrich and Stefan Blügel},
journal= {arXiv preprint arXiv:1103.5593},
year = {2015}
}