11 How do I plot the phonon dispersions?

Use what='scf_disp'. See example04. In this case you have to prepare an input for the ph.x code that must be called ph_control. The required information in this input is the q-point mesh used to interpolate the dynamical matrices and the name of the dynamical matrix files. See the ph.x guide if you need information on this point. The phonon dispersions are found in a file called output_disp.ps.g1 if the name of the postscript file is not given in the thermo_pw input. The vibrational density of states is found in a file called output_dos.ps.g1 if the name of the postscript file in not given in the thermo_pw input.