Request to clarify AMSET inputs

@rajanpir asks on GitHub:

  1. Using the command amset phonon-frequency, two frequencies were obtained max. freq and eff. freq. Shall we use the use max. frequency instead of eff.frequency for AMSET calculations which matches with examples cases like GaAs and Si.
  2. I understand that we can take the average of longitudinal elastic constants (C11 + C22 + C33) to determine the elastic constants. Please let us know whether full elastic tensor have been implemented in current version.
  3. Is it fine to calculate properties with AMSET without wave-functions dump option. I have included LORBIT=11 in my calculation and use only the vasprun.xml.


  1. You should use the effective polar frequency for AMSET calculations. This will compute the dipole generated by each phonon mode and use those to obtain an “effective frequency” that will better approximate the scattering.
  2. The full elastic constant is still not supported but should be available within ~1 week.
  3. It is fine to use the projections to calculate the overlap but not recommended. Using the wavefunction coefficients will be much more reliable. In the new version (to be released early next week) the process of generating the wavefunction coefficients will be much easier (and won’t require the pawpyseed package to be installed).

Thanks for the information. Please notify us in this forum when the new version is update.