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

### Re: Vacancy migration frequency

You are able to freeze atoms using the selective dynamics tags. Keep those same setting for the dynamical matrix calculation.