Bands and interbands inLaPd3andCePd3

A self-consistent calculation of the electronic structures of ${\mathrm{LaPd}}_3$ and ${\mathrm{CePd}}_3$ is presented. The method employed is that of the linear-muffin-tin orbitals with local-density approximation. The effects of spin-orbit coupling and those of 5p orbitals of La and Ce on the respective energy bands are studied. The energy bands and the density of states thus obtained are compared with available experimental data. The imaginary parts of the dielectric constant for the two compounds are calculated. The origins of different peaks in the optical spectra are traced back to interband transitions. The calculated optical properties of ${\mathrm{CePd}}_3$ compare favorably with many existing data. For ${\mathrm{LaPd}}_3$ some interesting optical peaks are obtained. This compound seems to be an ideal candidate to check the effects of 5p orbitals of La through optical measurements.