docs: def to_abivars(self):
          """Returns a dictionary with the abinit variables."""
          abivars = dict(
              gwcalctyp=self.gwcalctyp,
              ecuteps=self.ecuteps,
              ecutsigx=self.ecutsigx,
              symsigma=self.symsigma,
              gw_qprange=self.gw_qprange,
              gwpara=self.gwpara,
              optdriver=self.optdriver,
              nband=self.nband
              #"ecutwfn"  : self.ecutwfn,
              #"kptgw"    : self.kptgw,
              #"nkptgw"   : self.nkptgw,
              #"bdgw"     : self.bdgw,
          )
  
          # FIXME: problem with the spin
          #assert len(self.bdgw) == self.nkptgw
  
          # ppmodel variables
          if self.use_ppmodel:
              abivars.update(self.ppmodel.to_abivars())
  
          return abivars