[Pw_forum] Fwd: Help required

[Lorenzo Paulatto]

In data 30 luglio 2009 alle ore 20:13:13, Somesh Kumar Bhattacharya  
<somesh.kb at gmail.com> ha scritto:
> As I was trying too many things, I don't have the output files for all  
> cases
> .... but can  send you later


It is not necessary, actually the code is not crashing, but stopping.

I would say there is something seriously wrong with the calculation since  
the very beginning:
starting charge  261.71475, renormalised to  264.00000

Where has those 2.3 electrons gone? Although the code could still work, it  
seems like the initial conditions are too off the mark for the  
diagonalization algorithms.

I've tested the Cl pseudopotential on its own, and it looks like it is  
indeed lacking some charge. Also if you look at the header of the  
pseudopotential file you can spot a couple of inconsistencies.

If it is due to a recently introduced bug in QE or it has always been like  
that, I cannot say at the moment. It may be related to the 3D orbital  
being "almost" unbound for Cl with BLYP.

Anyway, I have generated another Cl BLYP NC pseudopotential, starting from  
the same parameters (although using the "normal" occupations) and it seems  
to be reliable. I'll send it to you visa private email, so you can run the  
basic tests. Otherwise, you can also try to start from random  
wavefunctions, instead of atomic ones.

Last but not least, for a highly inhomogeneous system, as yours, you  
should use 'local-TF' mixing, 'TF' mixing is for homogeneous system!

best regards

-- 
Lorenzo Paulatto
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