TDDFT run for EELS for q not zero

[hongtang2023]

Dear Yambo team,

I just want to ask if my input is correct or not for the EELS calculation at a q point which is not zero.
Please see attached output file, which also shows the input parameters.

Particularly, Please note the following three lines. It says optics. But I am doing q is not zero. Does q not zero still belong to the optics? Since we say, for optic calculations, q is zero. Is my calculation correct for the goal that I want to get the EELS for a q is not zero?

Code: Select all

 .-Input file  run_in_ALDA
 | optics                           %% [R] Linear Response optical properties
 | chi                              %% [R][CHI] Dyson equation for Chi.
 | tddft                            %% [R][K] Use TDDFT kernel

[Davide Sangalli]

Dear Dr. Hong Tang,
the input and the output look ok.

"optics" is just a label yambo uses to refer to calculations where the response function is computed.

Code: Select all

 | % QpntsRXd
 |   55 |  55 |                         %% [Xd] Transferred momenta
 | %

means the eels is computed for the q point number 55.

Also please notice that you are doing a TD-Hartree calculation, also called RPA+LF.
This is due to this input variable

Code: Select all

 | Chimod= "HARTREE"                %% [X] IP/Hartree/ALDA/LRC/PF/BSfx

If you want to perform a TDDFT calculation you need to set

Code: Select all

 | tddft                                    %% [R][K] Use TDDFT kernel
 | Chimod= "ALDA"                %% [X] IP/Hartree/ALDA/LRC/PF/BSfx
 

Best,
D.

[hongtang2023]

Dear Davide,

I am still trying TDDFT run for EELS for q not zero. I meet some questions I need your help.

1. for original Yambo.5.1.1 code, I do
"
tddft %% [R][K] Use TDDFT kernel
Chimod= "ALDA"
% QpntsRXd
1 | 10 | %% [Xd] Transferred momenta
%
"
I want to do EELS for q1 to q10. The ALDA kernel is q independent, it assumes q=0. So, with above input, I found that Yambo first calculate the Fxc kernel (q=0), then it calculates the eels for q1 to q10. The ALDA kernel ONLY was calculated for one time, before calculating eels for q1. For q2 to q10, Yambo just uses the first calculated kernel (q=0) for EELS for q2 to q10.
So, if I input
" % QpntsRXd
5 | 10 | %% [Xd] Transferred momenta
% "
Yambo still first calculate ALDA kernel with q=0,then do the EELS for q5 to q10.

Is the above understanding correct?



2. I modified tddft_alda_g_space.F file, in order to input a q dependent kernel MCP07. However, in the input for Yambo run, I still use ( but ALDA was modified with MCP07 in code)
"
tddft
Chimod= "ALDA"
"
This time, if I run for
"
% QpntsRXd
1 | 10 | %% [Xd] Transferred momenta
%
"
I found that Yambo first calculate MCP07 kernel with q=0, then do EELS for q1 to q10. But Yambo use the kernel evaluated with q=0 for Chi calculations for q2, q3, ...,q10 calculations ( note that q1=0,but q2 to q10 are not zero). This is not my purpose. I want Yambo calculate MCP07 kernel for a given q (q not zero).



3. continue with the above 2.
If I input
"
% QpntsRXd
5 | 5 | %% [Xd] Transferred momenta
%
"
then, I found that it looks that Yambo is calculating MCP07 kernel with q5, because I was able to code to get the value of q5 and send it to subroutine tddft_alda_g_space. However, after few seconds, Yambo met errors and stop.
The error are "
srun: error: nid004080: tasks 0-6: Segmentation fault
srun: Terminating StepId=25230019.0
slurmstepd: error: *** STEP 25230019.0 ON nid004080 CANCELLED AT 2024-05-06T01:51:30 ***
srun: error: nid004089: tasks 9-15: Segmentation fault
srun: error: nid004091: tasks 24-27,29-31: Segmentation fault
srun: error: nid004090: tasks 17-23: Segmentation fault
srun: error: nid004080: task 7: Terminated
srun: error: nid004090: task 16: Terminated
srun: error: nid004089: task 8: Terminated
...


"



Please let me know why I got this kind of errors.

I appreciate your help very much!

Best,
Hong