\begin{table}%t1
\caption{\label{hflines}\ion{Hf}{ii} lines considered in this work.}
\small%\centering
\par
\begin{tabular}{rrrr}
\hline\hline
\noalign{\smallskip}
 Wavelength & Transition & $E_{\rm low}$ & \loggf  \\
 nm         &            & eV\\
\hline\noalign{\smallskip}
 338.983 & a$^4$F--z$^2$P$^0$ & 0.45 & --0.78 \\
 356.166 & a$^2$D--z$^4$F$^0$ & 0.00 & --0.87 \\
 391.809 & a$^4$F--z$^4$D$^0$ & 0.45 & --1.14 \\
 409.315 & a$^4$F--z$^4$P$^0$ & 0.45 & --1.15 \\
\hline
\end{tabular}
\end{table}