Last step in Band Structure Calculation

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


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lyon0100
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Last step in Band Structure Calculation

#1 Post by lyon0100 » Mon Nov 23, 2009 6:30 am

I'm studying nanotubes. I first relax the ions and then run a static (NSW=0, IBRION=-1) selfconsistent calculation with a k-points file that points down the length of the nanotube (quazi 1-dimensional). I grab the DOS from that run and then perform another run with the new CHGCAR file using the value of ICHARG=11, changing the k-points file (still pointing down the tube but with more k-points).

My question is this: Do I need to change anything else in the INCAR file while I run it with ICHARG=11? What values should I have for NSW and IBRION? Are there any other errors in my procedure?

couldn't find anything in the manual. Appreciate the help.
Peter Lyon
Last edited by lyon0100 on Mon Nov 23, 2009 6:30 am, edited 1 time in total.

panda

Last step in Band Structure Calculation

#2 Post by panda » Tue Nov 24, 2009 11:45 pm

NSW = 0 for ICHARG = 11 -> Non-self-consistent run
IBRION and ISIF can be commented out b/c you are no longer doing a relaxation
Last edited by panda on Tue Nov 24, 2009 11:45 pm, edited 1 time in total.

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Last step in Band Structure Calculation

#3 Post by admin » Tue Dec 01, 2009 1:50 pm

for a non-scf run, the geometry should be kept, it makes no sense to 'relax' a structure with a fixed potentials
Last edited by admin on Tue Dec 01, 2009 1:50 pm, edited 1 time in total.

lyon0100
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Last step in Band Structure Calculation

#4 Post by lyon0100 » Wed Dec 02, 2009 7:57 pm

So when I calculate the Band Structure, I should leave IBRION=-1? Is that what you're refering to?
Last edited by lyon0100 on Wed Dec 02, 2009 7:57 pm, edited 1 time in total.

panda

Last step in Band Structure Calculation

#5 Post by panda » Mon Dec 07, 2009 6:22 pm

I think what he is saying is that when NSW = 0 that no ionic steps are performed, eg the geometry remains fixed so the choice of IBRION/ISIF is irrelevant - you already have your xtal structure from the scf calculation so you then only need to perform the non-scf to get the bands
Last edited by panda on Mon Dec 07, 2009 6:22 pm, edited 1 time in total.

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