PNNL

Abstract

We recently have developed a framework for implementing a scaled self-interaction corrected density functional theory (DFT-SIC) into pseudopotential plane-wave DFT. The technique implements the original method due to Perdew and Zunger by direct minimization of the DFT-SIC total energy functional. By using maximally localized Wannier functions, DFT-SIC calculation can be carried out efficiently even for extended systems. Using this new development the formation energies of defects in 3C-SiC were calculated and compared to more standard DFT calculations. Differences of up to 1eV were seen between DFT and DFT-SIC calculations of the formation energies. When compared to DFT, DFT-SIC produced less stable vacancies and silicon interstials, more stable antisites and carbon interstitials. The most favorable interstitials were found to be C interstitials in a C+-C dumbbell configuration, with the formation energy of 5.91eV with DFT and 5.65 eV with DFT-SIC. Si interstitials were not as stable as C interstitials. The most favorable Si interstitial was found to be Si tetrahedral surrounded by four C atoms, with a formation energy of 7.65eV with DFT and 8.71eV with DFT-SIC.