Time-dependent orbital-free density functional theory: Background and Pauli kernel approximations

Time-dependent orbital-free DFT is an efficient method for calculating the dynamic properties of large scale quantum systems due to low computational cost compared standard time-dependent DFT. We formalize this by mapping real system interacting fermions onto a fictitious non-interacting bosons. The Pauli potential and associated kernel emerge as key ingredients time-tependent Using uniform electron gas model system, we derive approximate frequency-dependent kernel. Pilot calculations suggest that space nonlocality feature Nonlocal terms arise already in second order expansion with respect unitless frequency reciprocal variable ($\frac{\omega}{q\, k_F}$ $\frac{q}{2\, k_F}$, respectively). Given encouraging performance proposed kernel, expect it will lead more accurate simulations nanoscale out equilibrium. Additionally, path formulate nonadiabatic kernels presents several avenues further improvements which can be exploited future works improve results.