Electronic structure of bcc Np, fcc Pu, Am, and Cm pure metals under pressure
has been investigated employing the LDA+U method with spin-orbit coupling
(LDA+U+SO). Magnetic state of the actinide ions was analyzed in both LS and jj
coupling schemes to reveal the applicability of corresponding coupling bases.
It was demonstrated that whereas Pu and Am are well described within the jj
coupling scheme, Np and Cm can be described appropriately neither in {m-sigma},
nor in {jmj} basis, due to intermediate coupling scheme realizing in these
metals that requires some finer treatment. The LDA+U+SO results for the
considered transuranium metals reveal bands broadening and gradual 5f electron
delocalization under pressure.Comment: 5 pages, 5 figure