Electronic structure of non-centrosymmetric superconductor LaPdSi3 and its reference compound LaPdGe3

• Fully relativistic DFT calculations of electronic structures of LaPdSi3 and LaPdGe3.
• Effects of antisymmetric spin–orbit coupling on band structures.
• Similar, multi-band Fermi surfaces (FS) obtained for both systems.
• Larger nested area of the FS in superconducting LaPdSi3.
• Negligible electron–phonon enhancement in non-superconducting LaPdGe3.

Electronic structures of a superconductor without inversion symmetry, LaPdSi3, and its non-superconducting counterpart, LaPdGe3, have been calculated employing the full-potential local-orbital method within the density functional theory. The investigations were focused on analyses of densities of states at the Fermi level in comparison with previous experimental heat capacity data and an influence of the antisymmetric spin–orbit coupling on the band structures and Fermi surfaces (FSs) being very similar for both considered here compounds. Their FSs sheets originate from four bands and have a holelike character, but exhibiting pronounced nesting features only for superconducting LaPdSi3. It may explain a relatively strong electron–phonon coupling in the latter system and its lack in non-superconducting LaPdGe3.