Dear Juzar Thingna, * Thanks !* * Actually, I have ever tried to calculate the frequency band in GHz with the energy ranging from 0 eV to 5 eV. * *To get the GHz band data, I have to set a smaller BrodenEnergy. The result is that I have to accept a larger output * *file--filename.EPSIMG. Then I input the filename.EPSIMG, I get a larger e2.dat. Siesta warns that "Too many * *frequency points". As the high frequencies points are not what I need, I intercept the low frequencies points as a new e2.dat.* *With the new e2.dat, I use optical to calculate it and get the results.I am not sure the results are right. Is my behavior reasonable ? * *With so many frequencies points, Siesta completely can't calculate. In another word, how can we deal with this problem?* * * *Best Wishes!* * * *Gonerfar * 2010/11/8 Juzar Thingna <[email protected]>
> Hi Gonefar, > > The sum rule (its the integral of the dipole strength=total number of > electrons) is generally a check. > > >I have to calculate the energy ranging from 0 eV to 20 eV or much higher > .Then I select the data what I need such as 0 eV ~ 2 eV. Is it right ? > > Yes this is correct. > > > If I want to calculate much lower frequency band such as GHz or MHz, > Siesta can't work ? > > If your calculation is correct you will get the response of the system from > 0 to 2 eV correctly, which means all frequencies upto 482 THz. > > Regards, > > Juzar Thingna > Department of Physics, > Center for Computation Science and Engineering, > National University of Singapore. > > > > > On Mon, Nov 8, 2010 at 7:15 PM, gonefar Yu <[email protected]> wrote: > >> Dear Sushil Auluck, >> Thank you very much! >> Does it mean Siesta can't calculate the energy ranging from 0 eV >> to 2 eV? And if I want to get the material's electromagnetic character >> ranging from 0 eV to 2 eV, I have to calculate the energy ranging from 0 eV >> to 20 eV or much higher .Then I select the data what I need such as 0 eV ~ 2 >> eV. Is it right ? >> Suddenly, another question comes to me. As we know 1 eV equals >> about 241 THz. If I want to calculate much lower frequency band such as GHz >> or MHz, Siesta can't work ? >> >> Best Wishes! >> >> Gonefar >> 2010/11/8 Sushil Auluck <[email protected]> >> >> hi, >>> increase the max energy to 20 eV or even higher...as you go higher the >>> sum rule will approach 100%.... >>> s.auluck >>> >>> > Dear All, >>> > Recently, I was using optical part to calculate the >>> > graphene's electromagnetic character. I set Optical.EnergyMinimum 0 eV >>> and >>> > Optical.EnergyMaximum 2 eV.However, in the output file it appears "Fsum >>> > rule >>> > is not fulfilled by more than a 20% The dielectric function will be >>> > extended >>> > to higher energies by enforcing the Fsum rule This will increase the >>> > quality >>> > of the quantities calculated via the Kramers-Kroning relation." Then >>> the >>> > result such as reflectance.out, the energy is extended to 0 eV ~ 200 eV >>> > while it should be 0 eV ~ 2 eV. As a new user, I am very confused about >>> > that. >>> > I am eager to know how can I avoid the warning and get the energy >>> > range what I need such as 0 eV ~ 2 eV. >>> > Thanks. >>> > >>> > Yours >>> > Gonefar >>> > >>> >>> >>> ....................................................................... >>> Prof. Sushil Auluck Phone:+91-512-6797092/6148 >>> Department of Physics +91-512-6798177(Home) >>> Indian Institute of Technology Cell :+91-9305548667 >>> Kanpur 208016 (UP) Fax :+91-512-6790914 >>> India >>> E-mail:[email protected]<e-mail%[email protected]> >>> ...............................................:[email protected] >>> http://www.iitk.ac.in/phy/People/phy_facvis.html >>> http://www.iitk.ac.in/phy/New01/profile_SA.html >>> ....................................................................... >>> ~ >>> >> >> >
