Page 1 of 1

Non-SCF Calculation

Posted: Wed Mar 08, 2006 5:09 pm
by aarondesk
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

Non-SCF Calculation

Posted: Thu Mar 09, 2006 10:44 am
by admin
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.

Non-SCF Calculation

Posted: Thu Mar 09, 2006 5:02 pm
by aarondesk
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.

Non-SCF Calculation

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

Non-SCF Calculation

Posted: Tue Mar 28, 2006 10:47 am
by admin
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.