Adsorption spectrums

[Sam-2025]

Dear all,


Like hBN, I tried to get adsorption spectrum for SrTiO3 and BaTiO3 related plot attached kindly for your consideration. As you can see there is a difference from experimental and my calculation. You think my result is not correct?

For electric field direction, I set 1 0 0. and for BSE bands I set 18 to 24(23 for BTO), considering the VBM=20, it means I selected 3 valence bands (18,19, and 20) and 4 conduction bands. So Yambo will do 3 x 4 transitions.
When I am choosing bands 10 to 23 or 24, I am getting even worse spectrum (and extra peaks) and my kpoint is 6 6 2, Because when I am using 12 12 4, it is crashing due to time limit even though I am using "mpirun -np 64", (input file attached for your consideration). Could you please guide me how can I analyze my result is correct or not? When there is extra peaks and the position of peals is not exactly match with experimental. Thank you so much for any guidance.

Also, I have to mention for BTO, I got the metallic system warning during the Yambo set up, but I was able to get the input file after that and run the calculation.

[Daniele Varsano]

Dear Samira,

according to the report file of one of your previous post, your k point grid was not recognized as uniform and gamma point only was considered. Regarding comparison with experiments, you should check the convergence parameter and provide yourself an interpretation of the results (depending on the experimental conditions, there could be effects not considered in the calculation as substrate/environment effects, defects etc....).

For electric field direction, I set 1 0 0. and for BSE bands I set 18 to 24(23 for BTO), considering the VBM=20, it means I selected 3 valence bands (18,19, and 20) and 4 conduction bands. So Yambo will do 3 x 4 transitions.

Please note that the number of transition are NvxNc*Nk(full BZ).

Best.

Daniele

[Sam-2025]

Thank you so much. I will check the converge parameters. also when I used the uniform kpoint, it worked. I sincerely appreciate it.