Identification and Resolution of Unphysical Multielectron Excitations in the Real-Time Time-Dependent Kohn-Sham Formulation

Abstract

We resolve a fundamental issue associated with the conventional Kohn-Sham formulation of real-time time-dependent density functional theory. We show that unphysical multielectron excitations, generated during time propagation of the Kohn-Sham equations due to fixation of the total number of Kohn-Sham orbitals and their occupations, result in incorrect electron density and, therefore, wrong predictions of physical properties. A new formulation is proposed in that the number of Kohn-Sham orbitals and their occupations are updated on the fly, the unphysical multielectron excitations are removed, and the correct electron density is determined. The correctness of the new formulation is demonstrated by simulations of Rabi oscillation, as analytical results are available for comparison in the case of noninteracting electrons.

References in corpus (5)

• Efficient formalism for large scale ab initio molecular dynamics based on time-dependent density functional theory
• Non-linear phenomena in time-dependent density-functional theory: What Rabi physics can teach us
• Time-resolved spectroscopy in time dependent density functional theory: An exact condition
• Ab Initio Molecular Dynamics on the Electronic Boltzmann Equilibrium Distribution
• Angular momentum transport with twisted exciton wave packets