On 31 January 2013 08:32, Wei-Bing Zhang <weibingzhangavh at gmail.com> wrote:
> (i.e vc-relax directly and > atomic relaxation with different lattice parameters). > Dear Wei, please triple-check that you are doing everything correctly: * that after the relax you are putting back the final parameters in the pw input * that in the SCF calculation that precedes the phonon one, forces and stress are actually zero I would also suggest to NOT play to input parameters: you are using input_dft and exx_div_threatement both of which do not apply in your case. Finally, ecutwfc = 65 is incredibly high for a Si ultrasoft pseudopotential. Try to read something about this subject i.e. here < http://www.stanford.edu/~hkulik/www/Tutorials/Entries/2012/4/17_Convergence_101.html> (the "dual" is ecutrho/ecutwfc) bests -- Dr. Lorenzo Paulatto IdR @ IMPMC -- CNRS & Universit? Paris 6 phone: +33 (0)1 44275 084 / skype: paulatz www: http://www-int.impmc.upmc.fr/~paulatto/ mail: 23-24/4?16 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 05 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20130131/793096f9/attachment.html
