Screened Coulomb interactions in metallic alloys. II. Screening beyond the single-site and atomic-sphere approximations

• A quantitative description of the configurational part of the total energy of metallic alloys with substantial atomic size difference cannot be achieved in the atomic-sphere approximation: It needs to be corrected at least for the multipole-moment interactions in the Madelung part of the one-electron potential and energy. In the case of a random alloy such interactions can be accounted for only by lifting the atomic-sphere and single-site approximations, in order to include the polarization due to local environment effects. Nevertheless, a simple parametrization of the screened Coulomb interactions for the ordinary single-site methods, including the generalized perturbation method, is still possible. We obtained such a parametrization for bulk and surface NiPt alloys, which allows one to obtain quantitatively accurate effective interactions in this system.

Ämnesord

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Nyckelord

generalized-perturbation method

1st-principles statistical-mechanics

coherent-potential approximation

effective cluster interactions

total-energy calculations

vacancy-formation energy

short-range-order

wave basis-set

electronic-structure

first-principles

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)