Search found 9 matches

by xi007
Mon Nov 05, 2018 4:09 am
Forum: VTSTTools
Topic: Force convergence problem
Replies: 2
Views: 14434

Re: Force convergence problem

Here are my vaspgr files. Thank you very much in advance!
by xi007
Mon Nov 05, 2018 2:38 am
Forum: VTSTTools
Topic: Force convergence problem
Replies: 2
Views: 14434

Force convergence problem

Dear Admin,

My CI-NEB calculations are not converging. I am trying to moving one H atom on the SiC surface into the subsurface. I used 7 images in the process and with one Gamma point calculation.The optimizer I used is IOPT=2. But after 1000 steps, the NEB is still not converged. It shows that the ...
by xi007
Fri Sep 18, 2015 1:34 pm
Forum: VTSTTools
Topic: CINEB system shift
Replies: 4
Views: 13096

Re: CINEB system shift

[quote="graeme"]Something is clearly inefficient with the optimizer. So yes, do check with IOPT=3 or 7 (first-order optimizers) until the forces drop below 1 eV/Ang and then if you go back to IOPT=1, try reducing the INVCURV parameter (note that this variable is not correct in your INCAR file).

And ...
by xi007
Thu Sep 17, 2015 4:48 pm
Forum: VTSTTools
Topic: CINEB system shift
Replies: 4
Views: 13096

Re: CINEB system shift

Thanks very much for your quick reply. I will try to do that. And here is the other files
by xi007
Thu Sep 17, 2015 2:38 pm
Forum: VTSTTools
Topic: CINEB system shift
Replies: 4
Views: 13096

CINEB system shift

Dear All,

Recently, when I used the CINEB to study the migration barrier of defect, such as interstitial and vacancy, I found some strange problems. It is difficult to converge for some configurations. And then when I checked the configuration for each image, I found that the system has been shift ...
by xi007
Thu Jul 16, 2015 9:29 pm
Forum: Bader
Topic: Bader charge by using VASP and Siesta
Replies: 6
Views: 23431

Re: Bader charge by using VASP and Siesta

Dear Prof,

I'm very appreciate for your suggestions. Maybe that's the reason to get these results. Thanks again!
by xi007
Thu Jul 16, 2015 5:34 pm
Forum: Bader
Topic: Bader charge by using VASP and Siesta
Replies: 6
Views: 23431

Re: Bader charge by using VASP and Siesta

Dear Prof,

Thanks very much for your reply. after compared with the number of valence electrons of Si and C, it is found that the transfered charge for Si and C are -2.67|e| and 2.67|e|, indicating that the electronegativity for C element is higher than that of Si. This is agreement with the ...
by xi007
Thu Jul 16, 2015 4:18 pm
Forum: Bader
Topic: Bader charge by using VASP and Siesta
Replies: 6
Views: 23431

Re: Bader charge by using VASP and Siesta

Thanks for your quick reply. Yes, I used the method in your website. By adding LAECHG=.TRUE. in the INCAR, then get these AECCAR0,1,2 files, and then chgsum.pl AECCAR0 AECCAR2 to get the CHGCAR_sum, after that, use bader CHGCAR -ref CHGCAR_sum to get the ACF.dat result. I think the process is no ...
by xi007
Tue Jul 14, 2015 1:12 pm
Forum: Bader
Topic: Bader charge by using VASP and Siesta
Replies: 6
Views: 23431

Bader charge by using VASP and Siesta

Dear All,

Hi, recently I used vasp to calculate the bader charge for SiC and compared the results with those in Siesta. But I got a very different result. In vasp, I used the GGA function to get the bader charge, and my result is that the charge around Si is about 6.7e and C about 1.3e. But ...