[gpaw-users] Problem with workfunction calculation

[Fredric Granberg]

Hi!

I'm doing the exercise on calculating the workfunction for a aluminium  
surface on the homepage. It works fine with LDA also when I increase  
the vacuum layer. The problem arises when I use PBE and a vacuum layer  
bigger than or equal to 12.5A. When I run the work_function.py there  
appears some noise on both sides in the plot where the averaged  
effective potential is printed out. This will give a much higher  
workfunction than the one where there isn't any noise. The only thing  
changed from the original file on the homepage is the vacuum thickness  
and the xc='PBE'. Are there any parameters that should be changed to  
get rid of this problem? I also tried the same script with copper and  
got exactly the same problem.

Best regards
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Fredric Granberg

fredric.granberg at helsinki.fi
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