Dear users,
If I calculate energy barrier for vacancy migration, How Can one calculate vacancy migration frequency ?
Sincerely
Vacancy migration frequency
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Re: Vacancy migration frequency
Within the harmonic approximation, you need to calculate the normal mode frequencies at the reactant and saddle point. Then the attempt frequency for hopping is given by: v = Prod v_rs / Prod v_ts , where Prod is the product of all the positive frequencies v = w/2pi, rs is the reactant state and ts is the saddle point.
Re: Vacancy migration frequency
Dear Professor,
Is there any link to calculate normal mode frequency at reactant and saddle point?
Sincerely
Is there any link to calculate normal mode frequency at reactant and saddle point?
Sincerely
Re: Vacancy migration frequency
Dear Professor,
Can we use the INCAR tags to run vibrational frequency like IBRION = 5 or 6 in the same NEB run. Also Do we need to set selective dynamics like calculating mode in one direction like z.
Sincerely
Can we use the INCAR tags to run vibrational frequency like IBRION = 5 or 6 in the same NEB run. Also Do we need to set selective dynamics like calculating mode in one direction like z.
Sincerely

 Site Admin
 Posts: 1896
 Joined: Tue Apr 26, 2005 4:25 am
 Location: University of Texas at Austin
 Contact:
Re: Vacancy migration frequency
You are able to freeze atoms using the selective dynamics tags. Keep those same setting for the dynamical matrix calculation.