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fxc matrix elements
Posted: Mon Dec 02, 2013 9:37 am
by sivanr
Dear yambo developers,
I am a new user, and currently exploring your code- mainly for TDDFT applications.
I would like to observe the fxc matrix elements (within linear response), for example in your SiH4 tutorial.
Is this possible?
Many thanks, and best regards
Sivan Refaely-Abramson
PhD student
Weizmann Institute of Science, Israel.
Re: fxc matrix elements
Posted: Mon Dec 02, 2013 10:06 am
by Daniele Varsano
Dear Sivan,
the Fxc matrix elements are not stored in file, otherwise you will end up with an HD full very soon.
The TDDFT can be solved either in reciprocal space and in KS basis set. Depending on what implementations you are using you will have Fxc_GG' or <n|fxc|n'> matrix elements. Assuming you are interested in the latter, you can print them adding write commands in
the fxc matrix elements are calculated in tddft_alda_R_space function defined in
and called here in src/bse/K.F:
Code: Select all
if (BS_K_is_ALDA) H_res_x=H_res_x+&
& tddft_alda_R_space(iq,(/ic1,ic2/),(/ik1,ik2,ik1,ik2/),&
& (/iv1,iv2/),(/is1,is2,is1,is2/),1)
Hope it helps.
Best,
Daniele
Re: fxc matrix elements
Posted: Tue Dec 03, 2013 7:58 am
by sivanr
Dear Daniele,
Thank you for your quick reply!
Can you please also comment on how to print the first option, namely Fxc_GG'?
Sivan.
Re: fxc matrix elements
Posted: Tue Dec 03, 2013 11:22 am
by Daniele Varsano
Dear Sivan,
the Dyson equation:
\chi=\chi^0+\chi^0(v+Fxc)\chi
is solved here:
./src/pol_function/X_s.F
and the tddft kernel is calculated here:
/src/tddft/tddft_alda_g_space.F
through the libxc libraries.
Cheers,
Daniele
Re: fxc matrix elements
Posted: Wed Dec 04, 2013 7:51 am
by sivanr
Thanks a lot!
Sivan
Re: fxc matrix elements
Posted: Sun Mar 30, 2014 1:55 pm
by sivanr
Hello again,
I used to print the real-space fxc matrix elements following your instructions from above, namely from within the bse/K.F code.
However, ever since I am using the new 3.4.1 version, I am having troubles with applying it. In fact, it seems like the real-space tdlda calculation does not use the K.o binary at all.
Do the matrix-elements still being calculated using tddft_alda_r_space.F? Can you please advice me regarding where should I approach in order to write those elements?
Thanks a lot!
Sivan
Re: fxc matrix elements
Posted: Mon Mar 31, 2014 9:45 am
by Daniele Varsano
Dear Sivan,
please fill your signature with your affiliation.
The call to the alda kernel is still there:
./src/K.F
Code: Select all
462 ! :::ALDA (resonant):::
463 !
464 if (BS_K_is_ALDA) H_res_x=H_res_x+&
465 & tddft_alda_r_space(iq,(/ic1,ic2/),(/ik1,ik2,ik1,ik2/),&
466 & (/iv1,iv2/),(/is1,is2,is1,is2/),1)
467 !
468 ! :::ALDA (coupling):::
469 !
470 if (BS_K_is_ALDA) H_cpl_x=H_cpl_x+&
471 & tddft_alda_r_space(iq,(/ic1,ic2/),(/ik1,ik2,ik1,ik2/),&
472 & (/iv1,iv2/),(/is1,is2,is1,is2/),2)
473 !
you should add here your writing lines and recompile all.
Assure to do a make clean_all before reconfiguring and recompile the code.
Best,
Daniele