Density-matrix coupled time-dependent exchange-correlation functional approximations

TL;DR

This paper introduces a novel class of non-adiabatic approximations in time-dependent density functional theory that accurately capture dynamic features of the exchange-correlation potential, improving upon traditional adiabatic methods.

Contribution

It proposes a new approach based on the exact expression for the exchange-correlation potential, incorporating the one-body reduced density-matrix as a functional of the Kohn-Sham density-matrix.

Findings

Reproduces dynamical step and peak features in the exchange-correlation potential.

Demonstrates two examples of the new approximation methods.

Shows improved accuracy over adiabatic approximations.

Abstract

We present a new class of non-adiabatic approximations in time-dependent density functional theory derived from an exact expression for the time-dependent exchange-correlation potential. The approximations reproduce dynamical step and peak features in the exact potential that are missing in adiabatic approximations. Central to this approach is an approximation for the one-body reduced density-matrix as a functional of the Kohn-Sham density-matrix, and we demonstrate two such examples.