On Jul 3, 2008, at 4:45 AM, wangqj1 wrote: > Dear pwscf users;
Dear Mr. Unknown > Could someone tell me 'how to compute surface energy and adsorbed > energy '? I am afraid, this question would be more appropriate for your supervisor than for this forum. in any event, think of the definition of surface energy: "surface energy" = energy necessary to cut an infinite solid into two semi-infinite parts (or in many slabs, for that matter, provided you count properly the number of slabs). right? now you can calculate the energy of bulk system (the result is infiite: what you get is an energy per unit volume, or an energy per atom). you can also calculate the energy of a system made of many (infinite, because of periodic boundary conditions) slabs. The enrgy per atom will be different. the difference will be proprortional to the surface area ... can you see now how the calculation would proceed? The same would apply to "adsorption" (NOT "adsorbed") energy = energy of a surface (or a slam, for that matter) with an adsorbed molecule, minus the sum of energy of an isolated (clean) surface and of an isolated molecule. > whether the surface energy is the whole energy or not ? do not undesrtand what you mean. think of the definitiion above > I am looking forward to your advice . > Thanks! would be so kind as to provide your name and full affiliation, the next time you write to this forum? Thanks - SB > > > > > > ??????????Qosmio?????? > ??????_______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste http://www.sissa.it/~baroni / [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) La morale est une logique de l'action comme la logique est une morale de la pens?e - Jean Piaget Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20080703/9122ebff/attachment.htm
