[Pw_forum] problem releated to calculating elastic constants

[Stefano Baroni]

non-linear core corrections to XC energies may be an issue here - you  
may want to chack
cheers - SB

On Aug 8, 2008, at 12:57 PM, Hande Ustunel wrote:

> Dear Premlata,
>
> It's normal for LDA to underestimate the lattice but in your case  
> the error
> is about 4%. I would start to get nervous. One usually aims at 1 or  
> at most
> 2 percent. I suggest you try other pseudopotentials and/or try to  
> make sure
> that you are getting good fits for your Ecut, Nk, smearing (if  
> necessary)
> parameters. By a "good curve" I mean one which is not too bumpy.
>
> Best,
> Hande
>
> On Fri, 8 Aug 2008, premlata pandit wrote:
>
>> hello
>> the experimental lattice constant of Li2S is 10.7867 a.u.
>> and my calculated equlibrium lattice constant is 10.375 a.u. by  
>> using  LDA
>> pseudopotential in pwscf calculation.
>> can i use this lattice canstant to calculating  elastic constants?
>>
>>
>
>
>
> -- 
> Hande Toffoli
> Department of Physics
> Office 439
> Middle East Technical University
> Ankara 06531, Turkey
> Tel : +90 312 210 3264
> http://www.physics.metu.edu.tr/~hande
>
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---
Stefano Baroni - SISSA  &  DEMOCRITOS National Simulation Center -  
Trieste
http://www.sissa.it/~baroni / [+39] 040 3787 406 (tel) -528 (fax) /  
stefanobaroni (skype)

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