Correlation functions for time-dependent calculation of linear-response functions

TL;DR

This paper discusses the significance of selecting suitable correlation functions to improve the accuracy of linear-response calculations via Fourier transforms of time-dependent correlation functions, demonstrated through dielectric function computations of silicon.

Contribution

It highlights the importance of correlation function choice in numerical accuracy and applies this insight to dielectric function calculations of silicon using a specific time-dependent method.

Findings

Proper correlation function selection reduces numerical errors.

Application to silicon dielectric functions demonstrates improved accuracy.

Supports the effectiveness of the time-dependent method by Iitaka et al.

Abstract

We emphasize the importance of choosing an appropriate correlation function to reduce numerical errors in calculating the linear-response function as a Fourier transformation of a time-dependent correlation function. As an example we take dielectric functions of silicon crystal calculated with a time-dependent method proposed by Iitaka et al. [Phys. Rev. E 56, 1222 (1997)].