sorry, but this time I do not understand what you mean ... S> On Apr 30, 2008, at 11:56 AM, lan haiping wrote:
> Thank you ,Stefano! > I have misinterpreted the meaning of effective mass. > When we talk about NFE states, does it mean that such > E-K dispersion should be held between 2 symmetry points, like from X- > > Gamma ? > > On Mon, Apr 28, 2008 at 1:40 AM, Stefano Baroni <baroni at sissa.it> > wrote: > The higher the energy, the lower the effect of the pseudopotential, > so high-energy states are expected to be more free-electron like > than low-lying ones. I am afraid that the very ocncept of "effective > mass" is not very meaningful for these states. However, I would > expect (although I have never verified) that for high-lying states > the derivative of the band energy with respect to the wavenumber be > linear with respect to the wavenumber, with the coefficient given by > the inverse of the free-electron mass. SB > > On Apr 27, 2008, at 8:27 AM, lan haiping wrote: > >> Dear All, >> >> I am wondering about the nearly free electron states . To identify >> such states, >> does it mean that its effective mass is very close to free >> electron ,And we can identify >> it from bands' dispersion ? >> >> Bests >> H.P >> >> -- >> Hai-Ping Lan >> Department of Electronics , >> Peking University , Bejing, 100871 >> lanhaiping at gmail.com, hplan at pku.edu.cn >> _______________________________________________ >> 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 > [+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 > > > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > > > > -- > Hai-Ping Lan > Department of Electronics , > Peking University , Bejing, 100871 > lanhaiping at gmail.com, hplan at pku.edu.cn > _______________________________________________ > 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 [+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/20080504/a21b10c1/attachment.htm
