Both accurate and precise

We present a new set of oscillator strengths for 142 $\ion{Fe}{ii}$ lines in the wavelength range 4000–8000 Å. Our gf-values are both accurate and precise, because each multiplet was globally normalized using laboratory data (accuracy), while the relative gf-values of individual lines within a given multiplet were obtained from theoretical calculations (precision). Our line list was tested with the Sun and high-resolution ($R \approx 10^5$), high-S/N (≈700–900) Keck+HIRES spectra of the metal-poor stars HD 148816 and HD 140283, for which line-to-line scatter (σ) in the iron abundances from $\ion{Fe}{ii}$ lines as low as 0.03, 0.04, and 0.05 dex are found, respectively. For these three stars the standard error in the mean iron abundance from $\ion{Fe}{ii}$ lines is negligible ($\sigma_\mathrm{mean} \leq 0.01$ dex). The mean solar iron abundance obtained using our gf-values and different model atmospheres is $A_{\rm Fe} = 7.45 (\sigma = 0.02$)