[Wien] Problem in elastic constant calculation

[Peter Blaha]

I doubt that we can be of great help with this information.


> Respected Prof. P. Blaha Sir&  All Wien2k users,
> Sir, I am doing LSDA calculation on rare earth compound and
> I am facing some minor problem when I calculating elastic moduli.
> The first  problem is that bulk modulus is not coming as calculated in
>
> volume optimization.
> Sir may I request you to kindly give me any idea to get the approximate
> value.How can I increase the value of bulk modulus(C11,C12) in this
> patch. Sir, I have done so many calculation in which I found C44  negative
>
> but I resolved this problem.Sir I am unable to increase the bulk
> modulus.

You have to analyse your results. How did you "solve" your C44 problem ?
Maybe you need more points for the elastic constants or a different size
of the distortions,.....
Don't just lokk at numbers, but plot your results as function of distortion and
check if they are reliable, giving numerically stable fits,....

Sir, I also want to know that, If I do calculation of two different
> compound on two different port then can it effect each other. Sir, I will be

Port ?? Do you mean w2web ports ??

The important issue is the "directory" !! You can make in ONE directory only ONE
calculation at the same time.

But again: Before you ask several times, why don't you "test" it yourself ???
If you get the same results as if you do it one after the other, than you are save, if not, ...

-- 

                                       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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