LNOAUGXC: Difference between revisions

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:<math>\tau_{\sigma}=\frac{1}{2}\sum_{i}\nabla\psi_{i\sigma}^{*}\cdot\nabla\psi_{i\sigma}</math>  
:<math>\tau_{\sigma}=\frac{1}{2}\sum_{i}\nabla\psi_{i\sigma}^{*}\cdot\nabla\psi_{i\sigma}</math>  
should, in principle, be larger than the von Weizsäcker kinetic-energy density{{cite|kurth:ijqc:1999}}  
should, in principle, be larger than the von Weizsäcker kinetic-energy density{{cite|kurth:ijqc:1999}}  
:<math>\tau_{\sigma}^{\textrm{W}}=\left\vert\nabla n_{\sigma}\right\vert^{2}/\left(8 n_{\sigma}\right).</math>  
:<math>\tau_{\sigma}^{\textrm{W}}=\frac{\left\vert\nabla n_{\sigma}\right\vert^{2}}{8 n_{\sigma}}.</math>  
However, this may not always be the case, particularly within the PAW spheres, when the pseudo density is augmented with the compensation charge. If {{TAG|LNOAUGXC}}=.TRUE. is set in the {{FILE|INCAR}} file, then the pseudo density is not augmented, which should alleviate the breaking of the condition <math>\tau_{\sigma}^{\textrm{W}}<\tau_{\sigma}</math>.
However, this may not always be the case, particularly within the PAW spheres, when the pseudo density is augmented with the compensation charge. If {{TAG|LNOAUGXC}}=.TRUE. is set in the {{FILE|INCAR}} file, then the pseudo density is not augmented, which should alleviate the breaking of the condition <math>\tau_{\sigma}^{\textrm{W}}<\tau_{\sigma}</math>.


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<!--
[[Category:INCAR tag]][[Category:Exchange-correlation functionals]][[Category:meta-GGA]][[Category:Projector-augmented-wave method]]
[[Category:INCAR tag]][[Category:Exchange-correlation functionals]][[Category:meta-GGA]]
-->

Latest revision as of 11:02, 7 January 2025

LNOAUGXC = .TRUE. | .FALSE.
Default: LNOAUGXC = .FALSE. 

Description: LNOAUGXC specifies if a meta-GGA functional is evaluated with a density that is augmented or not.


The Kohn-Sham kinetic-energy density

should, in principle, be larger than the von Weizsäcker kinetic-energy density[1]

However, this may not always be the case, particularly within the PAW spheres, when the pseudo density is augmented with the compensation charge. If LNOAUGXC=.TRUE. is set in the INCAR file, then the pseudo density is not augmented, which should alleviate the breaking of the condition .

A violation of can make the calculations unstable, in particular with the TPSS family of functionals.

Mind:
  • This tag is available since VASP.6.5.0 and is a replacement of the compiler option -DnoAugXCmeta that was available until VASP.6.4.3.
  • This option may negatively affect the results, therefore it should be used only for functionals, e.g., TPSS, for which the breaking of the condition may lead to numerical problems.

Related tags and articles

METAGGA, LTBOUNDLIBXC

Examples that use this tag

References