Dear Lorenzo, Thank you for your help. I am still confused (I may be dump :-)). Yes, I agree that wavefunction at Gamma is real and thus will have a sign with it. However, |psi|^2 is a positive quantity. If we multiply |psi|^2 by sign(psi) (which is segno in the code), then |psi|^2*sign(psi) will have a sign of sign(psi). Why we want to have a sign with |psi|^2?
Best, Trinh > On Tue, August 4, 2009 04:20, vtmtrinh at caltech.edu wrote: >> I think I can hard code, adding a few lines to print out psi in real >> space. > > Dear MyTrin, > You definitely can! > >> >> There is one part in the code 'local_dos' I don't understand is the >> case >> where ', lsign=true', i.e. k=gamma and iflag=0, write >> |psi|^2*sign(psi), >> why |psi|^2 has to multiply by sign(psi). I read thru the code at this >> part, but I still could not get it. > > Maybe I've misunderstood your question, but that's exactly what the option > lsign is supposed to do. Wavefunctions in Gamma can be defined ti be real, > hence they have a well defined sign. Although, they can always be > multiplied by any complex number (-1 included) and still remain perfectly > good eigenvalues. > > cheers > > -- > Lorenzo Paulatto > SISSA & DEMOCRITOS (Trieste) > phone: +39 040 3787 511 > skype: paulatz > www: http://people.sissa.it/~paulatto/ > > > > ---------------------------------------------------------------- > SISSA Webmail https://webmail.sissa.it/ > Powered by SquirrelMail http://www.squirrelmail.org/ > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum >
