[Wien] Formation energy + some other querries!

[Peter Blaha]

> 1. We need to calculate the Formation energies for impurities in some
> semiconductor material. Thus an algebra with the total energies of different
> systems. I therefore need to know the zero of my energy. I am not able to find
> where this value is written. Should be in case.scf0. Can you please tell us
> where to look for average interstitial potential or the zero of energy for a
> particular case?

I don't think you need to know the zero of your energy. It is an arbitrary number.

> 2. This problem we are facing with the 06, 07 versions. Earlier, there was a
> provision in case.in1 file that unit could be specified and accordingly the
> k-list will be read from in1 or case.klist file. Now the program does not allow
> us to read the k-list from in1. Why such a change has been made? Actually I
> find that there is a rewind command for the specific unit and if it is unit 5,
> case.in1 is rewind and there is an error. I did not see any such problem on the
> mailing list. We also posted the question but there was no reply even after
> putting it 2-3 times. Hence I want to knwo if we are making any error or is
> there a problem. I will accordingly send you the actual files and the error we
> are getting.

Using unit=5 for the k-vector list is not recommended. It should still be possible,
but you need an extra line before the k-list (put 1.d-15) and the k-list must be in the new
format (4I10 instead of 4I5, check the new klist format).
Unfortunately the UG has not been updated properly.

> 3. We are also not able to run self-consistency for Monkhost mesh/ special
> k-points? Please guide us where to get the information regarding this. We are
> doing slab calculations and for the large supercell we wish to use Monkhost
> mesh for reducing the computations.

You can put ANY k-mesh into case.klist; specify TEMP (or GAUSS) for the Fermi-method
and run an scf-cycle. (KGEN produces a special point mesh anyway, only for centered
lattices it is different due to symmetry constrains).

-- 

                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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