Get the bandgap, either from the EIGENVAL or DOSCAR files

def get_band_gap(self):
        """Get the bandgap, either from the EIGENVAL or DOSCAR files"""
        if self.outcar is not None and self.eignval is not None:
            bandgap = VaspParser._get_bandgap_eigenval(self.eignval, self.outcar)
        elif self.doscar is not None:
            bandgap = VaspParser._get_bandgap_doscar(self.doscar)
        else:
            return None
        return Property(scalars=[Scalar(value=round(bandgap, 3))], units='eV')