[Pw_forum] about the output of the epsilon.x

[shuai]

Dear Paolo,

Thank you very much for your suggestion.

Best regards,

S. Zhao

On 2014年09月19日 22:50, Paolo Giannozzi wrote:
> On Fri, 2014-09-19 at 22:00 +0900, shuai wrote:
>
>> To whom has experience with epsilon.x
> not to me. Anyway, it took me 2' to follow "wmin" and "wmax" in code
> PP/src/epsilon.f90: in subroutine "grid_build", you have
>
>    ! set the energy grid
>    !
>    alpha = (wmax - wmin) / REAL(nw, DP)
>    DO iw = 1, nw
>        wgrid(iw) = wmin + iw * alpha
>    ENDDO
>
> which clearly shows that the first grid point is not wmin but
> wmin + (wmax-wmin)/nw (nw being the number of grid points). I
> guess this should be
>
>    alpha = (wmax - wmin) / REAL(nw-1, kind=DP)
>    DO iw = 1, nw
>        wgrid(iw) = wmin + (iw-1) * alpha
>    ENDDO
>
> Paolo
>
>> I calculated the dielectric tensor using epsilon.x and got the output
>> files described in the eps_man.pdf. the input is:
>>
>>    &inputpp
>>       outdir = '/'
>>       prefix = 'Si'
>>       calculation = 'eps'
>>    /
>>    &energy_grid
>>       smeartype = 'gauss'
>>       intersmear = 0.136d0
>>       intrasmear = 0.0d0
>>       wmax = 10
>>       wmin = 0
>>       nw = 200
>>       shift = 0
>>    /
>>
>>
>> But in the output files the values of the frequency are from 0.005 to 10
>> with an increment of 0.005, in total 200 values in accordance with the
>> 'nw = 200'. My question is how to set for getting the results of
>> frequency= 0?
>>
>> Thanks in advance.
>>
>> Sincerely,
>>
>> S. Zhao
>>

-- 
PhD student
Graduate School of Life Science and Systems Engineering
Kyushu Institute of Technology, Japan