def _log10_Inorm_extern_atmx(self, Teff, logg, abun):
        """
        Internal function to compute normal passband intensities using
        the external WD machinery that employs model atmospheres and
        ramps.

        @Teff: effective temperature in K
        @logg: surface gravity in cgs
        @abun: metallicity in dex, Solar=0.0

        Returns: log10(Inorm)
        """

        log10_Inorm = libphoebe.wd_atmint(Teff, logg, abun, self.extern_wd_idx, self.wd_data["planck_table"], self.wd_data["atm_table"])

        return log10_Inorm