On Oct 16, 2013, at 10:52 AM, Yue-Wen Fang <yuewen.fang at gmail.com> wrote:
> Dear pwscf users, > > I have got electrostatic potential, but I want to average the data to make > the curve more smoothly like FIG11 in this paper > http://prb.aps.org/abstract/PRB/v71/i23/e235317. But I haven't found correct > definition of average electrostatic potential from web of science up till > now. The problem has also troubled me for several days. I put the data of > electric potential alone Z in the attachments. If the data was plotted, it > would to be a curve like many waves, but I want to get a average one. > > Any suggestion is appreciated. > Thank you in advance. > potential-pw.txt > > > -- > ------------------------------------------------------------------------------------------------------------ > Yue-Wen FANG, PhD candidate > Key Laboratory of Polar Materials and Devices, Ministry of Education > East China Normal University > > > You can perform a planar average, which provides, for example in the case of a surface slab, the potential as a function of the coordinate in the direction normal to the surface itself. Of course, such a "microscopic average", say V(z), contains oscillations related with the atomistic structure of your system. The "smooth" average you want to build is instead a "macroscopic" average of V(z), which means obtaining a new function V'(z) where the oscillations are smoothed out when you choose a window for macroscopic average whose size is comparable with the plane distances. There are lot of papers describing this average procedure, e.g. PRL 61, 734 (1988); PRB 44, 5572 (1991); J. Vac. Sci. Technol. B 10, 1744 (1992); PRB 76, 035430 2007 ; ?. See espresso-5.0.2/PP/src/average.f90 for the numerical implementation of such an average procedure within Quantum-ESPRESSO. Giovanni -- **** PLEASE NOTICE THE NEW E-MAIL ADDRESS: giovanni.cantele at spin.cnr.it Giovanni Cantele, PhD CNR-SPIN c/o Dipartimento di Scienze Fisiche Universita' di Napoli "Federico II" Complesso Universitario M. S. Angelo - Ed. 6 Via Cintia, I-80126, Napoli, Italy Phone: +39 081 676910 Skype contact: giocan74 ResearcherID: http://www.researcherid.com/rid/A-1951-2009 Web page: http://people.na.infn.it/~cantele http://www.nanomat.unina.it -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20131016/dd234ac7/attachment.html
