Can tdep calculate how the group velocity of phonon branches changes with frequency at different temperatures?

[liudadie12138]

Dear Developers
I apologize for disturbing you. I recently encountered an issue while using tdep for calculations. I want to calculate how the group velocity of phonon branches changes with frequency at different temperatures, but when using tdep, it only outputs the results of group velocity along high-symmetry path. I checked the manual but didn't find any mention of how to perform this operation.
I wonder if I missed some instructions or if there truly isn't a way to directly calculate the relationship between group velocity and frequency at different temperatures. Or is it possible for me to transform the output results?
Thank you for taking the time to answer my question amidst your busy schedule. Wishing you all the best in your work.

[mjv500]

Hello, This is standard: you can check the hdf5 files when running dos mode with h5dump: the frequencies and velocities will be saved on the full grid. They correspond to the temperature chosen to generate the force constants, whether MD or canonical configuration based. The gnuplot files you have seen are for the high symmetry path, but to match omega to v you need both arrays ordered identically, as in the hdf5 file. M. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Professor Matthieu J Verstraete Fellow, American Physical Society <https://www.aps.org> Chair, Steering Committee, European Theoretical Spectroscopy Facility <https://www.etsf.eu> Alumnus Fellow, Young Academy of Europe <https://www.yacadeuro.org> <http://yacadeuro.org/> Institute for Theoretical Physics (ITP) Department of Physics Buys Ballot Gebouw/Building, Princetonplein 5, office University of Utrecht, 3584 CC Utrecht Phone: +31 30 253 5926 Secretariat: +31 30 253 5929 and ***@***.*** Group web page (Liège): http://www.nanomat.ulg.ac.be/ Nanomat lab, Q-Mat center, Université de Liège Département de Physique, Bat. B5a, 4/50 Allée du 6 août, 19 B-4000 Sart Tilman, Liège Belgium Phone : +32 4 366 90 17 European Theoretical Spectroscopy Facility <https://www.etsf.eu> (ETSF) Mail : ***@***.*** ***@***.*** ***@***.***

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On Sat, Jun 21, 2025, 17:35 liu12138 ***@***.***> wrote: *liudadie12138* created an issue (tdep-developers/tdep#149) <#149> Dear Developers I apologize for disturbing you. I recently encountered an issue while using tdep for calculations. I want to calculate how the group velocity of phonon branches changes with frequency at different temperatures, but when using tdep, it only outputs the results of group velocity along high-symmetry path. I checked the manual but didn't find any mention of how to perform this operation. I wonder if I missed some instructions or if there truly isn't a way to directly calculate the relationship between group velocity and frequency at different temperatures. Or is it possible for me to transform the output results? Thank you for taking the time to answer my question amidst your busy schedule. Wishing you all the best in your work. — Reply to this email directly, view it on GitHub <#149>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABWOT34XV4L75NACIBJQJZD3EV3SNAVCNFSM6AAAAAB72HXGGKVHI2DSMVQWIX3LMV43ASLTON2WKOZTGE3DKMJXGU3DMNQ> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>