High temperature phonon calculation

[sayantanu]

In Fig. 63 of the following example

"https://docs.quantumwise.com/tutorials/thermoelectrics_cnt_isotope/thermoelectrics_cnt_isotope.html"
 
phonon thermal conductance has been shown up to a maximum temperature of 2000k. Is calculation at such a high temperature really meaningful at ballistic transport regime.

[Petr Khomyakov]

It is very likely that phonon-phonon scattering becomes of relevance at such high temperature. However, that was not the purpose of the tutorial to find the temperature range of the validity of harmonic approximation for the phonon transport. It is rather meant to show how the temperature dependence can be studied in the ballistic electron transport approximation, using the QuantumATK.