potential energy calculation

[Nagat Elkahwagy]

Hi Lucas

 

Please, how can one calculate the potential energy using QWalk?
The value had been already calculated by Gamess but I want to know if QWalk can calculate it?

 

Thank you very much

 

Regards

Nagat

[Lucas Wagner]

Hi Nagat,

The total potential energy is the sum of the 'potential' and 'nonlocal' components reported by gosling.

Keep in mind that the statistical uncertainties for potential energy are typically much higher than the total energy. This is because of the zero variance property of wave functions near eigenstates; H\Psi/\Psi approaches a constant as \Psi approaches an eigenstate.

Cheers,

Lucas

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[Nagat Elkahwagy]

بتاريخ الخميس، 3 نوفمبر، 2016 12:01:20 م UTC+2، كتب Nagat Elkahwagy:

Hi Lucas

 

But please I want to calculate the potential energy at different interatomic distances (potential energy curve) for a diatomic molecule. If this mean that the best to calculate it from the Morse function by using the the values of dissociation energy and equilibrium bond length calculated with QWalk?

 

Many thanks

 

Regards

Nagat

[Lucas Wagner]

Hi Nagat,

I just realized this was a different question. Yes, if you want to know the potential energy surface of a diatomic molecule, you should vary the bond length and fit the total energies to a potential.

I have a paper on this at:

http://scitation.aip.org/content/aip/journal/jcp/126/3/10.1063/1.2428294

where we did this for a series of transition metal molecules.

Lucas

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