hi, if you look at the epsimg file the eps is given at different energies... dE is the difference between two sucessive energy values...either you can fix dE or N # of energy steps...for 0-20 eV dE=0.05 eV N=401. note that epsimg is not valid in the microwave range.... s.auluck
> Dear Sushil Auluck > * Thanks for your advice.* > * Your refered to ' dE ' , how can you set ' dE ' ? What I only know > setting 'dE' is by setting ' BrodenEnergy '.* > *You know, 0.05 eV equals about 12 THz which is much larger than GHz > frequency band. If I want to calculate * > *GHz band and set dE=0.00001eV(equal about 2.4 GHz)which is not small > comparing with GHz band. Then I only * > *calculate the energy from 0 eV to 1 eV, it will produce 10,000 points! > Siesta can't do it. * > In my last mail, I intercept the low frequencies points as a new > e2.dat, is it reasonable? > > Gonefar > > 2010/11/8 Sushil Auluck <saul...@iitk.ac.in> > >> hi, >> you can always reduce the grid points...that is for 0 - 20 eV if choose >> dE=0.05 eV...this will give you 20/0.05 +1 = 401 energy points......this >> will make the EPSIMG file small.... >> s.auluck >> >> >> > 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 <juza...@gmail.com> >> > >> >> 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 <gonefar2...@gmail.com> >> >> 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 <saul...@iitk.ac.in> >> >>> >> >>> 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:saul...@iitk.ac.in <e-mail%3asaul...@iitk.ac.in>< >> e-mail%3asaul...@iitk.ac.in <e-mail%253asaul...@iitk.ac.in>> >> >>>> ...............................................:saul...@gmail.com >> >>>> http://www.iitk.ac.in/phy/People/phy_facvis.html >> >>>> http://www.iitk.ac.in/phy/New01/profile_SA.html >> >>>> >> ....................................................................... >> >>>> ~ >> >>>> >> >>> >> >>> >> >> >> > >> >> >> ....................................................................... >> 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:saul...@iitk.ac.in<e-mail%3asaul...@iitk.ac.in> >> ...............................................:saul...@gmail.com >> http://www.iitk.ac.in/phy/People/phy_facvis.html >> http://www.iitk.ac.in/phy/New01/profile_SA.html >> ....................................................................... >> ~ >> > ....................................................................... 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:saul...@iitk.ac.in ...............................................:saul...@gmail.com http://www.iitk.ac.in/phy/People/phy_facvis.html http://www.iitk.ac.in/phy/New01/profile_SA.html ....................................................................... ~
