LNOAUGXC
LNOAUGXC = .TRUE. | .FALSE.
Default: LNOAUGXC = .FALSE.
Description: LNOAUGXC specifies if a METAGGA functional is evaluated with a density that is augmented or not.
The Kohn-Sham kinetic-energy density
- [math]\displaystyle{ \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[1]
- [math]\displaystyle{ \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 LNOAUGXC=.TRUE. is set in the INCAR file, then the pseudo density is not augmented, which should alleviate the breaking of the condition [math]\displaystyle{ \tau_{\sigma}^{\textrm{W}}\lt \tau_{\sigma} }[/math].
A violation of [math]\displaystyle{ \tau_{\sigma}^{\textrm{W}}\lt \tau_{\sigma} }[/math] can make the calculations unstable, in particular with the TPSS family of functionals.
Mind:
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