[Pw_forum] Bulk modulus calculation

[Sanjeev Gupta]

Hi

For bulk modulus, energy Vs lattice const., is always welcome.
Otherway, there are lot of discussions on PWSCF forum, as one of by Prof.
Eduardo Menendez.


http://exciting.wdfiles.com/local--files/lithium-energy-vs-strain-calculations/elastic-paper.pdf
and http://exciting-code.org/elastic

download it take espresso i/o files.

enjoy the day!

bests
sanjeev


On Thu, Mar 6, 2014 at 9:32 AM, vicky singh <kirtinandan07 at gmail.com> wrote:

> Dear QE users
>    I am calculating the bulk modulus using the ev.x executable. The bulk
> modulus obtained is extremely sensitive to the number of data i use in the
> lattice parameter vs energy table. if i use three values a-x, a, a+x, where
> a is the equilibrium lattice parameter and x is 0.01 or 0.02 bohr the value
> of bulk modulus is very high as compared to i use 5 or 10 data. Bulk
> modulus is the double derivative if energy w.r.t. equilibrium lattice
> parameter.
>    What should be the best method to obtain the bulk modulus of the
> system. Also if you can provide any tutorial or help to calculate other
> elastic constant it will be extremely helpful.
>
> Vicky Singh
> RA, Bangalore
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 
With Best Regards,

------------------------------------
Dr. Sanjeev Kumar Gupta
Fulbright Post-Doctoral Scholar
Dept. of Physics
Michigan Technological University
1400 Townsend Drive, Houghton
MI 49931, USA
------------------------------------
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20140306/78e2b5c1/attachment.html>