Self-interaction-free time-dependent density-functional theory for molecular multiphoton processes in intense laser fields

Abstract

We present a new time-dependent density functional theory (TDDFT) with optimized effective potential (OEP) and self-interaction-correction (SIC) for nonperturbative treatment of multiphoton and nonlinear optical processes of many-electron molecular systems in intense laser fields. The theory allows the elimination of the spurious self-interaction energy in the conventional DFT and TDDFT, providing an accurate description of both short- and long-range potential as well as reliable ground- and excited-state (static and dynamic) properties. The time-dependent OEP/SIC equation is solved by means of the extension of the time-dependent generalized pseudospectral technique to the molecular multicenter problems. High precision time-dependent wavefunctions with spectral accuracy can be obtained by this procedure with the use of only a modest number of spatial grid points. We apply the procedure to a case study of multiphoton ionization and high harmonic generation of H2 molecules in intense pulsed laser fields.