Band Calculations for Ce Compounds with AuCu3-type Crystal Structure on the basis of Dynamical Mean Field Theory: I. CePd3 and CeRh3

Abstract

Band calculations for Ce compounds with the AuCu 3 -type crystal structure were carried out on the basis of dynamical mean field theory (DMFT). The auxiliary impurity problem was solved by a method named NCA f 2 vc (noncrossing approximation including the f 2 state as a vertex correction). The calculations take into account the crystal-field splitting, the spin–orbit interaction, and the correct exchange process of the f 1 → f 0 , f 2 virtual excitation. These are necessary features in the quantitative band theory for Ce compounds and in the calculation of their excitation spectra. The results of applying the calculation to CePd 3 and CeRh 3 are presented as the first in a series of papers. The experimental results of the photoemission spectrum (PES), the inverse PES, the angle-resolved PES, and the magnetic excitation spectra were reasonably reproduced by the first-principles DMFT band calculation. At low temperatures, the Fermi surface (FS) structure of CePd 3 is similar to that of the band obtained by the local density approximation. It gradually changes into a form that is similar to the FS of LaPd 3 as the temperature increases, since the 4 f band shifts to the high-energy side and the lifetime broadening becomes large.