docs: def to_abivars(self):
          """Returns a dictionary with the abinit variables"""
          return {
                  # Spectral function
                  "nomegasf": self.nomegasf,
                  "domegasf": self.domegasf,
                  "spmeth"  : self.spmeth,
                   # Frequency mesh for the polarizability
                  "nfreqre"  : self.nfreqre,
                  "freqremax": self.freqremax,
                  "nfreqim"  : self.nfreqim,
                  "freqremin": self.freqremin,
                  }