UT theoretical chemistry code forum

Thanks for your reply, as You help me a lot from last year to now. Concerning to the problem, 1. I used POTIM=0.15, however , it did not work. I attach the calculation files in attachments and the picture shows the relationship between energy and steps. Should I use a smaller POTIM? 2.how to judge t...

how about POTIM=0.15?

Hi professor, I prepare to do a calculation than a atom moves in the surface between the two bulk. First, i use Ediff=1e-2, Ediffg=-0.3, IBRION=2, it works well. Second, i use Ediff=1e-5, Ediffg =-0.05, IBRION=2, it works well too. Third, i use Ediff=1e-5, Ediffg =-0.01, IBRION=1, the problem appear...

dear professor,
can you teach me how to judge the declining of energy? Is it by E0 in OZICAR?
Thanks for your attention and reply.

Thanks professor,best wishes for you

Dear Professore,
when i did my calculation with ISIF=2 and IBRION=1 to reach ediffg=-0.01, it was hard to converge which had converged by IBRION=2 with the criterion of ediffg=-0.3. Can you give me some suggestions? This troubles me for a long time.
Thanks for attention and reply.

dear professor, i find the results of normal and accurate are not same. therefore, i am wondering about how to choose this parameter. 1.is the prec the same as the one of Structural optimization？ 2.for Clneb, the accurate is better than normal? (the manual of vasp says 'PREC=Accurate increases the m...

as it is hard for charged vacancy to converge, how about doing calculation without setting nelect, then adding the nelect to do the vacancy with charge after the pre-converged structure? Is this method reliable ?
thanks for attention. 0.0

still not converge 0.0

thanks

will it make the system harder to converge by reducing ediff? ?
i have do the calculation with IOP=1, which is also helpless.
as for the vacancy without charge, i have never thought this before. but will not it still hard to converge after adding some charge?

thanks, i continued my calculation with IOP=7 for a long time, however, it does not converge. can you tell me how to judge whether it can converge or not? ‘(*>﹏<*)′
[attachment=0]neb.rar[/attachment]

yes, .... you are right, i will correct it in the successive calculation, how about doing a rough process with less accurate kpoints ,and switching it to a more accurate one with the converged contcar from the former calculation?

dear professor,
i am sure that the kpoints is the same, but it seems the energies differ from each other.....
as for the clneb, i should wait until it converges. But is there a appropriate parameter to improve the performance?
thanks for your attention and response.

dear professor,
when i did the calculation with iop=7 and timestep=0.05, after a long period it still fluctuated at about 0.1-0.5. I do not know how to improve my parameters, can you give me some advice? whether reduce the ediff or timestep will help a lot?[attachment=0]neb.rar[/attachment]