[Pw_forum] "eigenvalues not converged" warnings appear in one compilation but does not appear in another

[Paolo Giannozzi]

Short answer: no. Different compilers and (especially) different 
mathematical libraries may (and usually do) produce slightly different
numbers. As long as you converge to the same (or "sufficiently same")
results, nothing to worry about. The day you will write some serious
piece of code, however, keep this fact is mind.

Paolo

On Mon, 2015-01-12 at 15:45 +0300, Uri Argaman wrote:
> Dear QE users and developers
> 
> I compile QE version 5.0.3 on cluster with Intel compilers and I got
> no warnings in some PW calculation. When I run the same input in
> another machine with another compilation I got the warning: "c_bands:
> 1 eigenvalues not converged" several times. I want to mention that
> this warning did not appear in the last SCF cycle and there is no
> difference in the energy. There is a very small difference in the
> stress. Do I have something to worry about?
> 
> 

> 
> Uri Argaman
> 
> Ben-Gurion University of the Negev
> 
> Israel
> 
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-- 
 Paolo Giannozzi, Dept. Chemistry&Physics&Environment, 
 Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
 Phone +39-0432-558216, fax +39-0432-558222