Hierarchies of methods towards the exact Kohn-Sham correlation energy based on the adiabatic-connection fluctuation-dissipation theorem

Görling A (2019)


Publication Type: Journal article

Publication year: 2019

Journal

Book Volume: 99

Article Number: 235120

Journal Issue: 23

DOI: 10.1103/PhysRevB.99.235120

Abstract

A formal procedure to construct the contributions to the frequency-dependent density-density (potential-density) response function in a series expansion with respect to the coupling constant of the electrons is presented. The required input quantities are obtained from static perturbation theory along the adiabatic connection. The contributions to the response function up to a given order are shown to determine the corresponding contributions in a coupling constant expansion of the frequency-dependent exchange-correlation kernel, the key quantity in time-dependent density-functional theory (TDDFT) in the linear response regime. Both the frequency-dependent response function as well as the exchange-correlation kernel thus are accessible in an order by order fashion. By exploiting the relations between the expansions of the response function and the exchange-correlation kernel, various methods are proposed to calculate the Kohn-Sham correlation energy via the adiabatic-connection fluctuation-dissipation (ACFD) theorem, including a hierarchy of ACFD methods towards the exact Kohn-Sham correlation energy. For a recently introduced ACFD method relying on a truncated power series approximation of the correlation kernel, a formal justification for the underlying ansatz is provided. The presented formal approach to construct the exchange-correlation kernel in an order by order fashion not only represents a basis for new ACFD methods for the Kohn-Sham correlation energy but additionally is of interest to devise new TDDFT methods in the linear response regime.

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How to cite

APA:

Görling, A. (2019). Hierarchies of methods towards the exact Kohn-Sham correlation energy based on the adiabatic-connection fluctuation-dissipation theorem. Physical Review B, 99(23). https://dx.doi.org/10.1103/PhysRevB.99.235120

MLA:

Görling, Andreas. "Hierarchies of methods towards the exact Kohn-Sham correlation energy based on the adiabatic-connection fluctuation-dissipation theorem." Physical Review B 99.23 (2019).

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