[salmon-user:00395] HHG simulation with SBE module for SiO₂

[? 雅恬]

Dear SALMON Developers,

I am currently performing HHG simulations for SiO₂ . I used the SBE module of the SALMON code. The test calculation is based on the converged structural and electronic data of SiO₂(you recommend before）

During post-processing, I found that the calculated induced current obviously lacks high-frequency components, which makes it impossible to obtain effective high-order harmonic signals. I have checked basic input parameters and convergence settings many times, but this issue still exists.

Could you please kindly help analyze the possible causes of this problem? Any suggestions on parameter adjustment, numerical settings or physical model selection for HHG simulation via SBE module will be greatly appreciated.

Thank you very much for your time and support.

Best regards,

Yatian Ning

[Mitsuharu UEMOTO]

Dear Yatian Ning,

Please apologize for the delay in my response.

I have reproduced the issue you described in my own computational environment. It appears that the Velocity Gauge semiconductor Bloch solver currently implemented in SALMON may exhibit the lack of precision in high-energy region as you mentioned. Since fully reproducing complex band structures can be challenging, there have been reports where accuracy degrades depending on the material system.

Generally, increasing the number of basis functions used for expansion may systematically reduce these errors. Therefore, it might be possible to improve the results by increasing the `nstate` parameter in your current settings.

Additionally, I believe that the length-gauge solver recently implemented in SALMON could mitigate this issue. Please allow me a little more time to investigate this further.

Sincerely,
----
Mitsuharu UEMOTO (Assist.Prof. / Ph.D.)
E-mail: uem...@eedept.kobe-u.ac.jp Phone: 078-803-6497
Department of Electrical and Electronic Engineering,
Graduate School of Engineering, Kobe University
植本光治（うえもとみつはる）
神戸大学大学院工学研究科電気電子工学専攻
〒６５７ー８５０１ 神戸市灘区六甲台町１−１

________________________________________
差出人: ? 雅恬 <ytni...@outlook.com>
送信日時: 2026年6月1日 18:47
宛先: salmo...@salmon-tddft.jp
件名: [salmon-user:00395] HHG simulation with SBE module for SiO₂