Auxiliary density functional theory: From molecules to nanostructures

Abstract

The working equations of auxiliary density functional theory (ADFT) and auxiliary density perturbation theory (ADPT) are derived in the framework of the linear combination of Gaussian-type orbital expansion. The inclusion of hybrid functionals into ADFT is presented. Its extension for the calculation of magnetic properties is outlined. The ADFT and ADPT implementations in the density functional theory program deMon2k are discussed. Special attention is given to the efficient calculation of electron repulsion integrals in nanostructures. The use of ADFT and ADPT in first-principles Born-Oppenheimer molecular dynamics at the pico- to nanosecond time scale is reviewed. In particular, the long-standing mystery of the discrepancy between experiments and computations for the polarizability of small sodium clusters is resolved. Applications of the parallel deMon2k ADFT implementation to systems on the nanometer scale are reviewed. This includes Al-zeolites and giant fullerenes. It is shown that structures as large as C540 can be fully optimized within a few days without any symmetry constraints in the ADFT framework employing all-electron basis sets. The successful application of a hierarchical transition state finder for the study of selected sodium cluster rearrangements is presented, too.