Fast computation of the Kohn-Sham susceptibility of large systems

TL;DR

This paper presents a method to compute the Kohn-Sham susceptibility more efficiently, reducing the computational complexity from N^4 to a faster approach, thereby enabling better analysis of large hybrid systems in time-dependent density functional theory.

Contribution

The authors introduce a novel approach to calculate the Kohn-Sham susceptibility N times faster, significantly improving computational efficiency for large hybrid systems in TDDFT.

Findings

Susceptibility calculation reduced from N^4 to a faster method

Facilitates TDDFT response and optical spectra calculations for large systems

Potentially accelerates hybrid system simulations in computational chemistry

Abstract

For hybrid systems, such as molecules grafted onto solid surfaces, the calculation of linear response in time dependent density functional theory is slowed down by the need to calculate, in N^4 operations, the susceptibility of N non interacting Kohn-Sham reference electrons. We show how this susceptibility can be calculated N times faster within finite precision. By itself or in combination with previous methods, this should facilitate the calculation of TDDFT response and optical spectra of hybrid systems.