Hi Dario, Thanks. My unit cell already big contains 80 atoms, I will try to calculate using supercell.
Regards, Manu On Thu, Jul 21, 2016 at 4:02 PM, dario rocca <roc...@gmail.com> wrote: > Hi Manu, > The last release of the code does not allow for k-point sampling, that's > why you get an error message. > You would need to use a supercell. If you have done a gamma only > calculation for your system that's probably why you get a spectrum > that does not match at all experiments. > Additionally, the Bethe-Salpeter equation is considered the most accurate > method for bulk solids. > Best, > Dario > > On Thu, Jul 21, 2016 at 9:42 AM, Manu Hegde <mhe...@uwaterloo.ca> wrote: > >> Hi Dario, >> Thank you very much. I have done some calculations for UV-Vis (see >> attached) and it is no where matching my experimental results in case of >> bcc-In2O3. Is it due to pseudopotential (I have used PBE USPP)?. Also I am >> unable to BZ sampling on k-mesh and TDDFT shown me an error. >> >> Regards, >> Manu >> (University of Waterloo) >> >> On Wed, Jul 20, 2016 at 8:09 PM, dario rocca <roc...@gmail.com> wrote: >> >>> Dear Manu, >>> You can simply extract it with the command >>> $ grep "S(E)" prefix.plot_chi.dat > file_for_plot >>> and use your favorite program to plot it. >>> Best, >>> Dario >>> >>> On Wed, Jul 20, 2016 at 10:49 AM, Manu Hegde <mhe...@uwaterloo.ca> >>> wrote: >>> >>>> 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 <roc...@gmail.com> 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 < >>>>> sunghwancho...@gmail.com> 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 >>>>>> Pw_forum@pwscf.org >>>>>> http://pwscf.org/mailman/listinfo/pw_forum >>>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> Pw_forum mailing list >>>>> Pw_forum@pwscf.org >>>>> http://pwscf.org/mailman/listinfo/pw_forum >>>>> >>>> >>>> >>>> _______________________________________________ >>>> Pw_forum mailing list >>>> Pw_forum@pwscf.org >>>> http://pwscf.org/mailman/listinfo/pw_forum >>>> >>> >>> >>> _______________________________________________ >>> Pw_forum mailing list >>> Pw_forum@pwscf.org >>> http://pwscf.org/mailman/listinfo/pw_forum >>> >> >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum@pwscf.org >> http://pwscf.org/mailman/listinfo/pw_forum >> > > > _______________________________________________ > Pw_forum mailing list > Pw_forum@pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum >
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