On Fri, 2014-10-10 at 11:42 +0200, H. Lee wrote: > At least to me, this difference seems strange.
I have spent many hours tracking mysterious bugs that turned out to be due to different processors yielding different results ON EXACTLY THE SAME OPERATIONS ON THE SAME DATA. Can you see why I do not find such differences so strange? :-) Paolo > Regards. > > > H. Lee > > On Thu, Oct 9, 2014 at 10:02 PM, Paolo Giannozzi > <[email protected]> wrote: > On Thu, 2014-10-09 at 20:29 +0200, H. Lee wrote: > > > Is this just an inevitable numerical noise? > > very likely. Some numerical noise is always there, it > is usually almost invisible, especially at scf convergence. > In some known cases of special sensitivity to truncation > and roundoff errors: noncolinear, spin-orbit, DFT+U, it > is more visible while self-consistency is reached. No > easy solution is known (to me at least) > > > P. > > -- > Paolo Giannozzi, Dept. Chemistry&Physics&Environment, > Univ. Udine, via delle Scienze 208, 33100 Udine, Italy > Phone +39-0432-558216, fax +39-0432-558222 > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum -- Paolo Giannozzi, Dept. Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
