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
>> .......................................................................
>> ~
>>
>
>

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