Category:ACFDT: Difference between revisions

From VASP Wiki
(Simplify piped link to plain lowercase link (MediaWiki first-letter case-insensitive))
 
(7 intermediate revisions by 2 users not shown)
Line 1: Line 1:
== Theory ==
The adiabatic connection fluctuation-dissipation theorem (ACFDT) provides access to the correlation energy of a system. It is often used as a synonym for the random-phase approximation (RPA), which can be understood as an infinite sum of all bubble diagrams in Feynman's diagrammatic language, where excitonic effects are neglected. RPA/ACFDT is used as a post-processing tool on top of a DFT calculation to obtain a more accurate ground-state energy. This category is part of [[many-body perturbation theory]].
RPA stands for the random phase approximation is often used as synonym for the adiabatic connection fluctuation dissipation theorem (ACFDT). RPA/ACFDT provides access to the correlation energy of a system and can be understood in terms of Feynman diagrams as an infinite sum of all bubble diagrams, where excitonic effects (interactions between electrons and holes) are neglected. The RPA/ACFDT is used as a post-processing tool to determine a more accurate groundstate energy.  


The following page contains more information about the theory behind RPA/ACFDT: {{TAG|RPA/ACFDT: Correlation energy in the Random Phase Approximation}}.
For the theoretical background, see [[RPA/ACFDT: Correlation energy in the Random Phase Approximation]]. For a practical step-by-step guide, see [[ACFDT/RPA calculations]].


== How to ==
*ACFDT: {{TAG|ACFDT/RPA calculations}}.


----
----


[[Category:VASP|ACFDT]][[Category:Many-Body Perturbation Theory|Many-Body Perturbation Theory]]
[[Category:VASP|ACFDT]][[Category:Many-body perturbation theory]]

Latest revision as of 09:21, 19 March 2026

The adiabatic connection fluctuation-dissipation theorem (ACFDT) provides access to the correlation energy of a system. It is often used as a synonym for the random-phase approximation (RPA), which can be understood as an infinite sum of all bubble diagrams in Feynman's diagrammatic language, where excitonic effects are neglected. RPA/ACFDT is used as a post-processing tool on top of a DFT calculation to obtain a more accurate ground-state energy. This category is part of many-body perturbation theory.

For the theoretical background, see RPA/ACFDT: Correlation energy in the Random Phase Approximation. For a practical step-by-step guide, see ACFDT/RPA calculations.