Dear Lorenzo, Thanks very much for this answer. The informations about the ions system was the must important and I got it.
Thanks once again ******************************* Bertrand SITAMTZE YOUMBI Laboratory of Material Sciences Department of Physics University of Yaounde I-Cameroon *********************************** --- En date de?: Lun 26.10.09, Lorenzo Paulatto <paulatto at sissa.it> a ?crit?: De: Lorenzo Paulatto <paulatto at sissa.it> Objet: Re: [Pw_forum] System size ?: "PWSCF Forum" <pw_forum at pwscf.org> Date: Lundi 26 Octobre 2009, 18h20 In data 26 ottobre 2009 alle ore 18:03:00, Bertrand SITAMTZE? <siyouber at yahoo.fr> ha scritto: > What is the size of the system in QE calculations (1 unit cell, 2, 3,? > ....)? Dear Betrand, most of Quantum-ESPRESSO programs and utilities use a plane-wave basis set? and periodically boundary conditions: the size of the system is always? formally infinite. The ions are repeats infinite times whatever you put in? the unit cell. The periodicity of electronic wavefunctions is a slightly different story? which depends on the number and positions of the k-points. It is a bit? long to explain. I can go in details, if necessary (although not tonight? for lack of time), but it would be better for you to study it off some? solid-state book first and ask for the necessary clarifications. best regards -- Lorenzo Paulatto SISSA? &? DEMOCRITOS (Trieste) phone: +39 040 3787 511 skype: paulatz www:???http://people.sissa.it/~paulatto/ ? ???*** save italian brains *** ? http://saveitalianbrains.wordpress.com/ _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20091027/4bc1892d/attachment.htm
