ttadano / alamode

Ab initio simulator for thermal transport and lattice anharmonicity
http://sourceforge.net/projects/alamode
MIT License
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calculate phonon lifetime by analyze_phonons.cpp #74

Closed ybC007 closed 2 years ago

ybC007 commented 2 years ago

Hi! I use analyze_phonons.py to calculate phonon lifetime data. But I found one problem and don't know the reason. If two phonon modes at the same k-point have the same frequency, then the result of analyze_phonons.py show that they have the same phonon lifetime, which is calculated by the mean value of anharmonic phonon linewidths of the two phonon mode, but they they have different thermal conductivity with the same group velocity. I can't the corresponding code to average the phonon lifetime in the analyze_phonons.cpp and don't know the reason. 😭 For example, phonon mode of ik=2 ,is=1 and phonon mode of ik=2, is=2 at 100K, the phonon lifetime of them is fomula

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