Self-Interaction correction using Fermi-Lowdin orbitals: Methodology and Parallelization

Density functional theory is a popular electronic structure method that can handle comparatively much larger systems than quantum chemical methods. However, density functional approximations suffer from self-interaction errors which limits its reliability for certain properties. The Perdew-Zunger (PZ) self-interaction correction (SIC) method removes self-interaction on an orbital by orbital basis and is computationally expensive. Recent implementation of Fermi-Lowdin orbital based SIC (FLOSIC) is a promising method that removes many computational complexities of PZ-SIC. We present some details of the FLOSIC methodology and present parallelization strategies using MPI+MPI and recent shared memory features of MPI-3 to make efficient use of large supercomputers. Using this implementation, we achieved parallel efficiency above 80% for 3360 processors. Applications of the FLOSIC method using the FLOSIC code on water clusters and carbon fullerenes will be presented.