Boltzmann transport equation

hi dear administrators and users
hope that all EPW community doing well

i have a question about the carrier concentration ncarrier , i know in the input this value is fixed (1.10 d+13) for the metals but the question why we use it particularly and how we get this value.



Best regards

Hello,

In the case of metal, you should use the input variable

assume_metal = .true.

In that case the variable ncarrier is not used since the number of carrier is determined based on the Fermi-Dirac distribution at the Fermi level.
In the code you can track the variable assume_metal to understand better what is being done as well.

Best wishes,
Samuel