Recent New Developments of Steady‐State and Time‐Dependent Density Functional Theories for the Treatment of Structure and Dynamics of Many‐Electron Atomic, Molecular, and Quantum Dot Systems

Abstract

AbstractWe present a short account of recent new developments of density‐functional theory (DFT) for accurate and efficient treatments of the electronic structure and quantum dynamics of many‐electron systems. The conventional DFT calculations contain spurious self‐interaction energy and improper long‐range potential, preventing reliable description of the excited and resonance states. We present a new DFT with optimized effective potential (OEP) and self‐interaction‐correction (SIC) to overcome some of the major difficulties encountered in conventional DFT treatments using explicit energy functionals. The OEP‐SIC formalism uses only orbital‐independent single‐particle local potentials and is self‐interaction free, providing a theoretical framework for accurate description of the excited‐state properties and quantum dynamics. Several applications of the new procedure are presented, including: (a) the first successful DFT treatment of the atomic autoionizing resonances, (b) a relativistic extension of the OEP‐SIC formalism for the calculation of the atomic structure with results in good agreement with the experimental data across the periodic table (Z = 2–106), (c) electronic structure calculation of the ionization properties of molecules, and (d) the delicated “shell‐filling” electronic structure in quantum dots. Finally we present also new formulations of time‐dependent DFT for nonperturbative treatment of atomic and molecular multiphoton and nonlinear optical processes in intense and superintense laser fields. Both the time‐independent Floquet approach and the time‐dependent OEP‐SIC technique are introduced. Application of the time‐dependent DFT/OEP‐SIC procedure to the study of multiple high‐order harmonic generation processes in intense ultrashort pulsed laser fields is discussed in detail.