[CP2K:4868] Re: optimization problem of a supercell

Florian Schiffmann flosch... at gmail.com
Wed Jan 8 09:57:31 UTC 2014


Dear Mohammed,

usually I do not complain about the way people post their questions. I your 
case I might give you an advise:
All people in this forum are volunteers and it can take some time to figure 
out what is going on or as Ari said people might simply be on holidays. 
This means you can't expect to get an aswer and therefore such posts as 
above are pointless and might even discourage people to help you. In 
general it is a better idea to ask politely for help and provide all 
details (input, output) in the first place.
Second, similar questions have been asked before and browsing the forum you 
might get already some ideas about possible solutions. The golden rule is, 
try to help yourself and if you are really stuck ask for help.

To make clear what I mean:
Having a quick look at your input file three points immediatly show up 
which should always be tested:
1) a PW cutoff of 250 is definitely not converged. Test convergence!
2) you use the default scf convergence criterium. For optimizations 
(especially stress tensor) tighter WFN convergence might be needed. Again 
test convergence
3) your cell is very small 6x6x10. As you perform Gamma point only 
calculations test k-point convergence

Steps 1-3 are essential for what ever you do. 

If the problem still exists try to a different optimizer. If the problem 
still exists ask you question again and people might be more willing to 
look into it.

Sorry for being a bit harsh but I think you should know.

Flo

  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20140108/d9bbd888/attachment.htm>


More information about the CP2K-user mailing list