\begin{table}%t6 \caption{\label{lifetimesNbIII} HFR lifetimes ($\tau$~in~ns) (without and with core-polarization effects included) of the low-lying levels of Nb~III (4d$^2$5p~configuration). Only lifetime values larger than 1~ns are quoted.} \par %\centering \par \begin{tabular}{ccccc} \hline\hline\noalign{\smallskip} $E$ (cm$^{-1}$)\tablefootmark{a} & Term\tablefootmark{a} & $J$ & $\tau$ (HFR) & $\tau$ (HFR+CPOL) \\ \hline\noalign{\smallskip} 63 686.7 & $^4$G$^{\circ}$ &5/2 & 2.25 & 2.58 \\ 65 005.9 & $^4$G$^{\circ}$ &7/2 & 2.13 & 2.44 \\ 65 904.2 & $^4$F$^{\circ}$ & 3/2 & 1.01 & 1.16 \\ 66 456.2 & $^4$G$^{\circ}$ &9/2 & 2.02 & 2.32 \\ 66 598.4 & $^2$F$^{\circ}$ &5/2 & 1.21 & 1.39 \\ 67 094.1 & $^4$F$^{\circ}$ &5/2 & 1.20 & 1.37 \\ 67 775.0 & $^2$D$^{\circ}$ &3/2 & 1.17 & 1.33 \\ 68 061.7 & $^4$G$^{\circ}$ &11/2 & 1.96 & 2.25 \\ 68 382.1 & $^2$F$^{\circ}$ &7/2 & 1.56 & 1.78 \\ 69 110.4 & $^2$D$^{\circ}$ &5/2 & 1.20 & 1.37 \\ 74 726.7 & $^4$D$^{\circ}$ &1/2 & 1.40 & 1.62 \\ 75 383.1 & $^4$D$^{\circ}$ &3/2 & 1.02 & 1.13 \\ 76 387.8? & $^2$D$^{\circ}$ &5/2 & 1.00 & 1.16 \\ 76 913.3? & $^2$D$^{\circ}$ &3/2 & 1.03 & 1.20 \\ 77 247.5 & $^2$F$^{\circ}$ & 5/2 & 1.28 & 1.46 \\ 78 085.9 & $^4$P$^{\circ}$ &1/2 & 1.16 & 1.34 \\ 78 372.2 & $^4$P$^{\circ}$ &3/2 & 1.20 & 1.38 \\ 79 429.7 & $^4$P$^{\circ}$ &5/2 & 1.18 & 1.35 \\ 82 152.1 & $^2$H$^{\circ}$ &11/2 & 1.33 & 1.52 \\ 84 523.0 & $^2$F$^{\circ}$ &7/2 & 1.08 & 1.23 \\[2pt] \hline \end{tabular} \tablefoot {\tablefoottext{a}{From Iglesias (\cite{iglesias2}).}} \end{table}