Hello Dario, I have done the similar calculations, it went well, after running turbo_spectrum.x Do you have any code to extract S(E) or I have to do it manually?
Manu (University of Waterloo) On Tue, Jul 19, 2016 at 8:24 PM, dario rocca <[email protected]> wrote: > Dear SungHwan, > please refer to > http://arxiv.org/pdf/1402.0486.pdf > and > > http://urania.sissa.it/xmlui/bitstream/handle/1963/5797/turboTDDFT-CPC.pdf?sequence=1 > for more details. > > In the output of the postprocessing chi_1_1 is the xx component of the > dynamical polarizability, chi_1_2 the xy component, etc. > Often chi is indicated as \alpha in the papers. > Specifically you would have > > Component energy of the perturbation real part of > chi imaginary > (indicated either as E or \omega) > chi_1_1= 0.000000000000000E+00 0.955769346791472E+01 > 0.000000000000000E+00 > ......... > > As you correctly say the absorption spectrum is related to the imaginary > part of the average of chi multiplied by E (the energy E is often > indicated as \omega). > This averaged quantity is contained in S(E). Specifically S(E) is the > strength function defined as > S(E)=2m/(\pi*e^2*\hbar) * E*Im[chi(E)], where chi has been averaged over > the 3 spatial directions. > This definition is convenient because S(E) satisfies the f-sum rule. > So if you extract S(E) and plot it you will have the absorption spectrum. > Let me know if it's still not clear > Best, > Dario > > > > > On Tue, Jul 19, 2016 at 4:01 PM, SungHwan Choi <[email protected]> > wrote: > >> hi, I am a newbie for turboTDDFT. Now, I ran a simple example. It was >> assume. >> Now I have prefix.plot_chi.dat file. then I don't know how to generate >> absorption spectrum from that file and dielectric constant values. As far >> as I understood, the absorption spectrum is related to imaginary part of >> average \chi value. but in the file there are 9 values >> chi_1_1 >> chi_2_1 >> chi_3_1 >> chi_1_2 >> chi_2_2 >> chi_3_2 >> chi_1_3 >> chi_2_3 >> chi_3_3 >> This is 3*3*3 tensor. how do I get an absorption spectrum and dieletric >> constant values? by the way S(E) means what? >> >> Sincerely >> Sunghwan Choi >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum >> > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum >
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