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plot excite state transition density

Posted: Tue Sep 17, 2019 4:59 pm
by michele guerrini
Dear developers, I am asking you if it is possible to plot, by using ypp, the transition density (TD) for a certain excited state of an extended system, in the same way as it is possible to plot the exciton WF by fixing the position of the hole. Now, I tried to plot TD by using the keyword 'freehole' in the input but it plots just the modulus^2 of the TD, while I need instead the TD with sign. How can I do this ?
Many thanks

Re: plot excite state transition density

Posted: Wed Sep 18, 2019 8:46 am
by Daniele Varsano
Ciao Michele,

The "freehole" option is the way to go. By default ypp plot the square modulus. If you want the real and imaginary part you need to modify few lines in
ypp/excitons/excitons_WFs.F

Code: Select all

 do i_l=BS_E_degs(j_lambda),BS_E_degs(j_lambda)+n_lambda_deg-1
       !
       wf_ = V_dot_V(BS_H_dim,BS_mat(1,i_l),wf_vc)
       !
       v2plot(ir) = v2plot(ir)+abs(wf_)**2.
       !
enddo
in

Code: Select all

 do i_l=BS_E_degs(j_lambda),BS_E_degs(j_lambda)+n_lambda_deg-1
       !
       wf_ = V_dot_V(BS_H_dim,BS_mat(1,i_l),wf_vc)
       !
       v2plot(ir) = v2plot(ir)+real(wf_)
       !
enddo
and the same for the imaginary part. If you want to have both of them, you need to redefine v2plot as a complex or a two components vector in
/modules/mod_YPP.F and then modify accordingly the subroutines that operate the outputs that are in ypp/plotting

Best,
Daniele