The application of the nonlocal exchange potential matrix method to the study of ferromagnetic 3d transition metals

The matrix method of Tsai for the calculation of the nonlocal exchange potential has been extended to calculate the plain-wave expanded interstitial part using the Thomas-Fermi damping wave vector. We found enhancement of the 3d-band exchange splitting and consequently the magnetizations and magnetic moments relative to those obtained by LSDA. By resolving the valence electrons of the Fe, Co, and Ni atoms into spin-polarized s, p, and d components, we found depletion of the itinerant 4sp electrons that enhances the minority-spin localized d electrons, which is the main cause of the substantial reduction of the magnetic moments in the metals from those of free atoms. Using idealistic domain-wall-free structural models, the magnetizations of these three metals calculated by the exchange-matrix method are overestimated. The overestimates correlate with the exchange energies, which may play a determinative role in the sizes of domain walls.