Dear Eduardo Ariel Menendez Proupin, At first i relaxed nano-tube and obtain the position of carbon atoms in the ground state. Then i decrease the tube length. A in the relation is the area of nano-tube (A=pi*R*R which R is the radius of tube). F is the atomic force in the Z axis which can be calculated by using Q.E. I think it is better to calculate total energy in some configuration and use (F=dE/dz, where E is the total energy in different configuration). Is there any problem in this procedure?
On Thu, Sep 23, 2010 at 12:58 AM, Eduardo Ariel Menendez Proupin < eariel99 at gmail.com> wrote: > Hi, > I think we always know what WE do, but not all of what computers do :-(. > > Mohsen, did you relaxed the atoms after the compression? Why did you > calculate force and not stress. Have you used a finite nanotube and computed > the forces upon the atoms of the edge? Finally, how is defined A in > E=(F/A)/((L-L0)/L0) > for the case of a single nonotube? > Best regards > Eduardo > > Eduardo Menendez > Departamento de Fisica > Facultad de Ciencias > Universidad de Chile > Phone: (56)(2)9787439 > URL: > http://fisica.ciencias.uchile.cl/~emenendez<http://fisica.ciencias.uchile.cl/%7Eemenendez> > > Let's pray for the 33 trapped miners! Four months to rescue > > > >> ---------- Mensaje reenviado ---------- >> >> From: Stefano Baroni <baroni at sissa.it> >> To: PWSCF Forum <pw_forum at pwscf.org> >> Date: Wed, 22 Sep 2010 19:43:15 +0200 >> >> Subject: Re: [Pw_forum] Young's Modulus >> For that, also LRT akkows one to know what one is doing ... ;-) >> SB >> >> On Sep 22, 2010, at 7:30 PM, Mehmet Topsakal wrote: >> >> Dear Eyvaz, >> >> I think you omitted one more thing to mention. Brute-force method also >> allows one to know what he is doing. >> >> >> >> On Wed, Sep 22, 2010 at 8:14 PM, Eyvaz Isaev <eyvaz_isaev at yahoo.com> >> wrote: >> >>> Hi, >>> >>> Yes, you are right about Abinit for elastic constants calculations. The >>> main question is which method (Abinit or via total energy) is easier >>> and less time-consuming. >>> >>> Bests, >>> Eyvaz. >>> ------------------------------------------------------------------- >>> Prof. Eyvaz Isaev, >>> Department of Physics, Chemistry, and Biology (IFM), Linkoping >>> University, Sweden >>> Theoretical Physics Department, Moscow State Institute of Steel & Alloys, >>> Russia, >>> isaev at ifm.liu.se, eyvaz_isaev at yahoo.com >>> >> >>> > -- > > > . > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- Mohsen Modarresi, PhD student of Solid State Physics, Ferdowsi University of Mashhad, Iran. Phone +98-9133452131 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100923/d7060f3b/attachment.htm
