QMAXFOCKAE: Difference between revisions

Latest revision as of 05:27, 9 September 2026

QMAXFOCKAE = [real array]
Default: QMAXFOCKAE = 0

Description: Sets the wave vector at which the local augmentation charges are fitted to restore the all-electron charge density on the plane-wave grid.

The fit is part of shape restoration, and NMAXFOCKAE gives how many wave vectors are used. One value is read per species, in the order of the species in the POSCAR file.

The default, 0, is not itself a wave vector but a sentinel meaning leave the built-in values alone. As long as it is 0, the fit uses

6 Å^-1 for NMAXFOCKAE = 1, a plane-wave energy of approximately 140 eV,
5 and 10 Å^-1 for NMAXFOCKAE = 2, approximately 95 eV and 380 eV.

A positive value replaces the first wave vector. The second is always twice the first and cannot be chosen independently, so with NMAXFOCKAE = 2 the setting

QMAXFOCKAE = 4

fits at 4 and 8 Å^-1. With NMAXFOCKAE = 1 the single wave vector is taken from QMAXFOCKAE directly.

We do not recommend setting these values manually.

References

@@ Line 1: / Line 1: @@
-{{TAGDEF|QMAXFOCKAE|[real array] }}
+{{TAGDEF|QMAXFOCKAE|[real array]|0}}
-Description: The parameter {{TAG|QMAXFOCKAE}} controls at which wave vectors the local augmentation
+Description: Sets the wave vector at which the local augmentation charges are fitted to restore the all-electron charge density on the plane-wave grid.
-charges are fitted to obtain an accurate charge augmentation on the plane wave grid.
 ----
-We do not recommend to set these flags manually, except after careful inspection
+The fit is part of [[Projector-augmented-wave formalism#Shape restoration|shape restoration]], and {{TAG|NMAXFOCKAE}} gives how many wave vectors are used. One value is read per species, in the order of the species in the {{FILE|POSCAR}} file.
-of the vasp code (fast_aug.F). The default values are 6.0 Å<sup>-1</sup>
-if {{TAG|NMAXFOCKAE}}=1 (corresponding to 140 eV), and 5.0 and 10 Å<sup>-1</sup> (corresponding to 95 eV and 380 eV)
-for {{TAG|NMAXFOCKAE}}=2.
-== Related Tags and Sections ==
+The default, 0, is not itself a wave vector but a sentinel meaning ''leave the built-in values alone''. As long as it is 0, the fit uses
-{{TAG|NMAXFOCKAE}},
-{{TAG|LMAXFOCKAE}}, {{TAG|LFOCKAEDFT}}
+* 6 Å<sup>-1</sup> for {{TAG|NMAXFOCKAE|1}}, a plane-wave energy of approximately 140 eV,
+* 5 and 10 Å<sup>-1</sup> for {{TAG|NMAXFOCKAE|2}}, approximately 95 eV and 380 eV.
+A positive value replaces the '''first''' wave vector. The second is always twice the first and cannot be chosen independently, so with {{TAG|NMAXFOCKAE|2}} the setting
+ {{TAGBL|QMAXFOCKAE}} = 4
+fits at 4 and 8 Å<sup>-1</sup>. With {{TAG|NMAXFOCKAE|1}} the single wave vector is taken from {{TAG|QMAXFOCKAE}} directly.
+We do not recommend setting these values manually.
+== Related tags and articles ==
+{{TAG|NMAXFOCKAE}}, {{TAG|LMAXFOCKAE}}, {{TAG|LMAXFOCK}}, {{TAG|LFOCKAEDFT}}, {{TAG|LFOCKSTD}}, [[Projector-augmented-wave formalism]]
+{{sc|QMAXFOCKAE|Howto|Workflows that use this tag}}
+== References ==
+<references/>
+[[Category:INCAR tag]][[Category:Projector-augmented-wave method]]