Category:Meta-GGA: Difference between revisions

From VASP Wiki
No edit summary
No edit summary
Line 3: Line 3:
Meta-GGA exchange-correlation functionals depend on the electron density <math>n</math>, its first derivative <math>\nabla n</math> and the kinetic-energy density <math>\tau</math>:
Meta-GGA exchange-correlation functionals depend on the electron density <math>n</math>, its first derivative <math>\nabla n</math> and the kinetic-energy density <math>\tau</math>:
:<math>E_{\mathrm{xc}}^{\mathrm{meta-GGA}}=\int\epsilon_{\mathrm{xc}}^{\mathrm{meta-GGA}}(n,\nabla n,\tau)d^{3}r</math>
:<math>E_{\mathrm{xc}}^{\mathrm{meta-GGA}}=\int\epsilon_{\mathrm{xc}}^{\mathrm{meta-GGA}}(n,\nabla n,\tau)d^{3}r</math>
Although meta-GGAs are slightly more expensive than GGAs, they are still fast to evaluate and appropriate for very large systems. Furthermore, meta-GGAs can be more accurate than GGAs and more broadly applicable. Note that as in most other codes, meta-GGAs are implemented in VASP within the generalized KS scheme{{cite|yang:prb:2016|}}. The meta-GGA that is currently the most widely used in solid-state physics is SCAN{{cite|sun:prl:15|}}. The meta-GGA functionals using the Laplacian of the electron density, <math>\nabla^{2}\rho</math>, are not yet available in VASP.
Although meta-GGAs are slightly more expensive than GGAs, they are still fast to evaluate and appropriate for very large systems. Furthermore, meta-GGAs can be more accurate than GGAs and more broadly applicable. Note that as in most other codes, meta-GGAs are implemented in VASP within the generalized KS scheme{{cite|yang:prb:2016|}}. The meta-GGA that is currently the most widely used in solid-state physics is SCAN{{cite|sun:prl:15|}}. The meta-GGA functionals using the Laplacian of the electron density, <math>\nabla^{2}n</math>, are not yet available in VASP.


== How to ==
== How to ==

Revision as of 13:29, 6 April 2022

Theoretical Background

Meta-GGA exchange-correlation functionals depend on the electron density , its first derivative and the kinetic-energy density :

Although meta-GGAs are slightly more expensive than GGAs, they are still fast to evaluate and appropriate for very large systems. Furthermore, meta-GGAs can be more accurate than GGAs and more broadly applicable. Note that as in most other codes, meta-GGAs are implemented in VASP within the generalized KS scheme[1]. The meta-GGA that is currently the most widely used in solid-state physics is SCAN[2]. The meta-GGA functionals using the Laplacian of the electron density, , are not yet available in VASP.

How to

A meta-GGA can be used by specifying the tag METAGGA in the INCAR file.



Pages in category "Meta-GGA"

The following 18 pages are in this category, out of 18 total.