NGX: Difference between revisions

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Description: {{TAG|NGX}} sets the number of grid points in the FFT-grid along the first lattice vector.
Description: {{TAG|NGX}} sets the number of grid points in the FFT-grid along the first lattice vector.
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By default {{TAG|NGX}} is set in accordance with the requested "precision"-mode ({{TAG|PREC}}) and the plane wave kinetic energy cutoff {{TAG|ENCUT}}.
By default {{TAG|NGX}} is set in accordance with the requested "precision"-mode ({{TAG|PREC}}) and the plane wave kinetic energy cutoff {{TAG|ENCUT}}:
 
::{| cellpadding="5" cellspacing="0" border="1"
|{{TAG|PREC}} || {{TAG|NGX}}
|-
| Normal || 3/2&times;G<sub>cut</sub>
|-
| Single || 3/2&times;G<sub>cut</sub>
|-
| Accurate || 2&times;G<sub>cut</sub>
|-
| Low || 3/2&times;G<sub>cut</sub>
|-
| Medium || 3/2&times;G<sub>cut</sub>
|-
| High ||  2&times;G<sub>cut</sub>
|}
where
:<math>E_{\rm cut}=\frac{\hbar^2}{2m_e}G_{\rm cut}^2</math>
with E<sub>cut</sub>={{TAG|ENCUT}}.
 
 
Alternatively {{TAG|NGX}} may be set to a specific value in the {{FILE|INCAR}} file.  
Alternatively {{TAG|NGX}} may be set to a specific value in the {{FILE|INCAR}} file.  



Revision as of 12:35, 12 February 2011

NGX = [integer]
Default: NGX = set in accordance with PREC and ENCUT 

Description: NGX sets the number of grid points in the FFT-grid along the first lattice vector.


By default NGX is set in accordance with the requested "precision"-mode (PREC) and the plane wave kinetic energy cutoff ENCUT:

PREC NGX
Normal 3/2×Gcut
Single 3/2×Gcut
Accurate 2×Gcut
Low 3/2×Gcut
Medium 3/2×Gcut
High 2×Gcut

where

with Ecut=ENCUT.


Alternatively NGX may be set to a specific value in the INCAR file.

Related Tags and Sections

NGY, NGZ, NGXF, NGYF, NGZF, PREC, ENCUT, ENAUG, ENMAX


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