[Pw_forum] Does anybody have the same problem for the relax calculation about the atom force

[Lorenzo Paulatto]

In data 28 luglio 2009 alle ore 23:37:55, 文沈 <wshen02 at gmail.com> ha  
scritto:
> As follows, in the output file, it gives the force and 0.000000000 or
> *******.  I don't know why it doesn't give any correct force value.my  
> input

The **** are just a problem with the fortran format, it means that the  
forces are too large and won't fit in their respective fields.

>      Total force =          NAN     Total SCF correction =     0.000703

I'm more concerned about the NAN as total force, there may be several  
explanations for this (bug in QE, bugs in libraries)
The only advice I can give you at the moment is to increase the number of  
bands: you are using 280 bands for 508 electrons, which means you only  
have ~10% more bands than the bare minimum to fit all the electrons. This  
may not be enough to insure band occupations become negligible before the  
code runs out of bands (your smearing is 10mRy).
Also, you've not defined Hubbard_U for types 1 and 2, although I'm quite  
sure the code sets them automatically to zero.

best regards

-- 
Lorenzo Paulatto
SISSA  &  DEMOCRITOS (Trieste)
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