To assess various ionic-core approximations we carried out density functional calculations on a series of octahedral palladium and gold model clusters Mn with n = 13-147. We compared results for average bond lengths, cohesive energies, vertical ionization potentials, and electron affinities to the corresponding all-electron scalar relativistic results. We used extrapolated bulk values to compare with experiments. The results of the projector-augmented wave method agree best with the all-electron results. When modeling palladium-gold nanoalloy particles, one should keep in mind that current ECP or PAW modeling of palladium moieties appears to be more accurate than modeling of gold species. (C) 2013 Elsevier B. V. All rights reserved.