Category:Exchange-correlation functionals: Difference between revisions

From VASP Wiki
No edit summary
No edit summary
Line 19: Line 19:
***{{TAG|DFT-D2}}{{cite|grimme:jcc:06}}
***{{TAG|DFT-D2}}{{cite|grimme:jcc:06}}
***{{TAG|DFT-D3}}{{cite|grimme:jcp:10}}
***{{TAG|DFT-D3}}{{cite|grimme:jcp:10}}
***DFT-D4 (available as of VASP.6.2 as [[Makefile.include#DFTD4_.28optional.29|external package]])
***DFT-D4{{caldeweyher:jcp:2019}} (available as of VASP.6.2 as [[Makefile.include#DFTD4_.28optional.29|external package]])
**Methods from Tkatchenko, Scheffler et al.:
**Methods from Tkatchenko, Scheffler et al.:
***{{TAG|Tkatchenko-Scheffler method}}
***{{TAG|Tkatchenko-Scheffler method}}

Revision as of 12:20, 12 October 2023

In the KS formulation of DFT[1][2], the total energy is given by

where the terms on the right-hand side represent the non-interacting kinetic energy of the electrons, the electrons-nuclei attraction energy, the classical Coulomb electron-electron repulsive energy, the exchange-correlation energy and the nuclei-nuclei repulsion energy, respectively. The orbitals and the electron density that are used to evaluate are obtained by solving self-consistently the KS equations

The only terms in and in the KS equations that are not known exactly are the exchange-correlation energy functional and potential . Therefore, the accuracy of the calculated properties depends mainly on the approximations used for and . Several hundreds of approximations for the exchange and correlation have been proposed[3]. They can be classified into several types, like the local density approximation (LDA), generalized gradient approximation (GGA), meta-GGA, and hybrid. Functionals that include van der Waals corrections have also been proposed. More details on the different types of approximations available in VASP and how to use them can be found in the pages and subcategories listed below.

How to

References

Subcategories

This category has the following 5 subcategories, out of 5 total.

Pages in category "Exchange-correlation functionals"

The following 119 pages are in this category, out of 119 total.