Non-SCF Calculation

Queries about input and output files, running specific calculations, etc.


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aarondesk
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Non-SCF Calculation

#1 Post by aarondesk » Wed Mar 08, 2006 5:09 pm

I have wavefunctions (WAVECAR) from a previous calculation and would like to perform a non-self consistent calculation with these wavefunctions on a new geometry configuration.

I've looked through the manual and the only reference I can find for non-self consistent calculations is for ICHARGE =10,11,12, which seems to work only from a CHGCAR file.

Of course, I can always set ISTART = 1, NELM = 1, and NELMIN = 1 and this should calculate the energy of my new geometries using the old wavefunction.

Am I missing anything here?

Thanks,
Aaron
Last edited by aarondesk on Wed Mar 08, 2006 5:09 pm, edited 1 time in total.

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Non-SCF Calculation

#2 Post by admin » Thu Mar 09, 2006 10:44 am

the old WAVEFUN can ONLY be used if the setup of the calculation which wrote the file is exactly the same as the setup of the calculation which continues : same
cell dimensions,
PREC,
k-points,
continue from CONTCAR as the new start geometry,... .
If you change ANY of these parameters (like the k-meshes,...) please continue from CHGCAR.
Last edited by admin on Thu Mar 09, 2006 10:44 am, edited 1 time in total.

aarondesk
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Non-SCF Calculation

#3 Post by aarondesk » Thu Mar 09, 2006 5:02 pm

Perhaps I wasn't clear in my original message. I'm trying to calculate the reorganization energy from Marcus theory. This involves using the wavefunctions from geometry 1 and calculating the energies of geometry 2 using that same wavefunction. Hence, I need to calculate the energy of a new geometry (POSCAR) using an old wavefunction (WAVECAR).

Is this possible?

Setting NELM = 1, and NELMIN = 1 doesn't seem to be working - this calculates one SCF step and I want zero SCF steps. I just want the energies from a fixed wavefunction.

Thank you.
Last edited by aarondesk on Thu Mar 09, 2006 5:02 pm, edited 1 time in total.

aarondesk
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Non-SCF Calculation

#4 Post by aarondesk » Thu Mar 09, 2006 5:03 pm

Just to follow up - the Kpt, cell dimensions, PREC, etc. are all the same for the new geometry. Only the atom positions change.
Last edited by aarondesk on Thu Mar 09, 2006 5:03 pm, edited 1 time in total.

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Non-SCF Calculation

#5 Post by admin » Tue Mar 28, 2006 10:47 am

no, I's sorry that is not possible. in WAVECAR, only the coefficients of the wavefunctions are stored, not the wavefucntions themselves. Therefore really EVERYTHING has to be compatible in order that the information read from WAVECAR makes sense.
Last edited by admin on Tue Mar 28, 2006 10:47 am, edited 1 time in total.

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