Dear Dr Blaha and Dr Cottenier, Thanks for your suggestions. I think I have enough information to get the job done.
Fhokrul > Date: Thu, 25 Feb 2010 17:44:14 +0100 > From: pblaha at theochem.tuwien.ac.at > To: wien at zeus.theochem.tuwien.ac.at > Subject: Re: [Wien] problem with DOS calculations > > I guess we had these questions before. > > The TETRAHEDRON method calculates the DOS band by band. > With one k-point a "band" consists only of ONE energy and thus would give a > delta function. In other words: even if your eigenvalues are at 0.099999 > (band 1) and 0.100001 > (band 2), the DOS from tetra at 0.10000 is exactly zero (while the integrated > DOS (see Stefaans comment) > will increase by 2 electrons for the energies 0.099 and 0.100. > > For one k-point, one needs a "histogramm method", i.e. you should specify an > energy mesh (eg. 0.005 Ry), > then take case.energy (or case.qtl) and then simply "count" the eigenvalues > in each interval (remember, > the DOS is the number of states/energy intervall). Finally you may smoothen > the curve and put some > gauss broadening on it. > > > Stefaan Cottenier schrieb: > > > >> Addendum: you can take the intermediate output, put them into a > >> spreadsheet such as Excel and plot the dos yourself with some > >> broadening -- it works but is not so convenient. > > > > Two comments on this: > > > > 1) you can specify a broadening in case.int (see Sec. 8.1.3 of the UG) > > > > 2) there is a very robust integration of the DOS plotted in > > case.outputt. Even if the energy step is too large to see a spike, it > > will appear clearly as a sudden jump of the integrated value. > > > > Stefaan > > _______________________________________________ > > Wien mailing list > > Wien at zeus.theochem.tuwien.ac.at > > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > > -- > ----------------------------------------- > Peter Blaha > Inst. Materials Chemistry, TU Vienna > Getreidemarkt 9, A-1060 Vienna, Austria > Tel: +43-1-5880115671 > Fax: +43-1-5880115698 > email: pblaha at theochem.tuwien.ac.at > ----------------------------------------- > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien _________________________________________________________________ Hotmail: Free, trusted and rich email service. https://signup.live.com/signup.aspx?id=60969 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20100226/8476ba17/attachment.htm>