Here are below my comparison of Kpts Vs Energy for a cubic
cell. I tried to get the convergence for K Points. Strangely I observe that the energy raises by 2 eV after 111 (gamma entered mesh) and then converges. But still the energy with 111 K mesh is the lowest. I sense something going wrong. Can anyone help?
111 1 F= -.66907977E+03
222 1 F= -.66729831E+03
333 1 F= -.66723281E+03
444 1 F= -.66723296E+03
555 1 F= -.66723406E+03
666 1 F= -.66723441E+03
777 1 F= -.66723433E+03
888 1 F= -.66723534E+03
999 1 F= -.66723446E+03
Kpoints Vs Energy
Moderators: Global Moderator, Moderator
-
kmkumar
- Newbie
- Posts: 29
- Joined: Wed Jul 23, 2008 12:03 pm
Kpoints Vs Energy
Last edited by kmkumar on Mon Apr 22, 2013 2:55 pm, edited 1 time in total.
-
Faculty22
Kpoints Vs Energy
As far as I know and experienced, the lowest energy on kpoints convergence test has no meaning! Sometimes during KPT convergence test energy increase/decrease! The point is to exclude/minimise the variation of energy by choosing an adequate kpoint.
What I advice you also to do always do is: calculate the total energy/atom per each kpoint test and compare!! E.g. in your care, I guess kpoint 333 or to be a bit more safe 555 works definitely fine!
What I advice you also to do always do is: calculate the total energy/atom per each kpoint test and compare!! E.g. in your care, I guess kpoint 333 or to be a bit more safe 555 works definitely fine!
Last edited by Faculty22 on Tue May 14, 2013 3:46 am, edited 1 time in total.