Dear all,
I have some questions about the "aliasing errors". I have set PREC=accurate in INCAR, but there are still warnings in the OUTCAR. Why?
For example, in one job, I set PREC=accurate. The info written in OUTCAR is
dimension x,y,z NGX = 84 NGY = 80 NGZ = 210
dimension x,y,z NGXF= 168 NGYF= 160 NGZF= 420
I would recommend the setting:
dimension x,y,z NGX = 83 NGY = 79 NGZ = 208
The FFT grid with 83, 79, 208 is approximaly 2G_cut. So the actual values used in calculation 84, 80 and 210 have already exceeded the 2G_cut. But in the following there are two warnings
WARNING: aliasing errors must be expected set NGX to 86 to avoid them
WARNING: aliasing errors must be expected set NGY to 82 to avoid them
Can I ask why this warning happen?
Is there any parameters in INCAR which can guarantee to avoid "aliasing errors"? It seems that PREC=accurate is not enough.
Thanks!
Best,
Binglun
How to completely avoid "aliasing errors"?
Moderators: Global Moderator, Moderator
-
- Newbie
- Posts: 11
- Joined: Fri Jan 15, 2016 6:30 pm
-
- Newbie
- Posts: 10
- Joined: Wed Nov 25, 2015 2:38 pm
- License Nr.: 5-2233
Re: How to completely avoid "aliasing errors"?
Dear Binglun,
You can set the values of NGX, NGY and NGZ by hand in the INCAR. I would recommend to do this if aliasing errors arise.
All the best,
Declan
You can set the values of NGX, NGY and NGZ by hand in the INCAR. I would recommend to do this if aliasing errors arise.
All the best,
Declan
-
- Newbie
- Posts: 11
- Joined: Fri Jan 15, 2016 6:30 pm
Re: How to completely avoid "aliasing errors"?
dscullion12 wrote:Dear Binglun,
You can set the values of NGX, NGY and NGZ by hand in the INCAR. I would recommend to do this if aliasing errors arise.
All the best,
Declan
Thanks Declan,
Yes, this is one way to solve this problem.
But it would be better if the some INCAR parameter can guarantee no aliasing errors from scratch.
Best,
Binglun