Frozen Density Embedding with External Orthogonality in Delocalized Covalent Systems

摘要: Frozen density embedding (FDE) has become a popular subsystem functional theory (DFT) method for systems with weakly overlapping charge densities. The failure of this strongly interacting and covalent is due to the approximate kinetic energy (KEDF), although need KEDFs may be eliminated if each subsystem’s Kohn–Sham (KS) orbitals are orthogonal other, termed external orthogonality (EO). We present an implementation EO into FDE framework within Amsterdam program package, using level-shift projection operator method. generalize remove orbital localization schemes include multiple subsystems, we show that exact KS-DFT energies densities reproduced through iterative freeze-and-thaw cycles number systems, including delocalized benzene molecule starting from atomic subsystems. Finally, examine possibility truncated basis...