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Will the NEB code be successfully builded into VASP5.2?
Posted: Fri Sep 25, 2009 3:09 am
by ross
Dear everyone:
We just got the new version vasp5.2,I want to know whether the NEB code now available compatible with it.
Best regards
ross
Re: Will the NEB code be successfully builded into VASP5.2?
Posted: Fri Sep 25, 2009 5:47 am
by graeme
yes it can; we have not seen any problems yet
Re: Will the NEB code be successfully builded into VASP5.2?
Posted: Fri Sep 25, 2009 12:33 pm
by ross
[quote="graeme"]yes it can; we have not seen any problems yet[/quote]
Hi, graeme:
I have another question,that is, during the neb calculation, it need the perpendicular component of the true force ,but how does it get the true force, does it get the true force directly from the OUTCAR of vasp which is the derivative of the free energy.
best regards
ross
Re: Will the NEB code be successfully builded into VASP5.2?
Posted: Fri Sep 25, 2009 3:52 pm
by graeme
It uses the force that is printed in the OUTCAR. This is the derivative of the energy, not the free energy.
Re: Will the NEB code be successfully builded into VASP5.2?
Posted: Sat Sep 26, 2009 6:39 am
by ross
[quote="graeme"]It uses the force that is printed in the OUTCAR. This is the derivative of the energy, not the free energy.[/quote]
hi,graeme,I have checked that in section 7.5 of vasp handbook, it mention that "the finite tempeture LDAforces are defined as the derivative of the generalized free energy". I am not sure whether this is just right for the smearing methords. If that is true, when I use the smearing methord during NEB run, NEB run use the derivative of the free energy as the true force.
Re: Will the NEB code be successfully builded into VASP5.2?
Posted: Sat Sep 26, 2009 7:45 pm
by graeme
Ah yes, you are right. The extrapolation for T->0 to get the energy is not done with the forces. So the forces are consistent with the free energy and not the T->0 energy.