\begin{table}%T3
\caption{Dependences of $\R I2$: least-square fit parameters (with a
constant term).}
\label{tab:lsf}
%\centering
\par
\small
\begin{tabular}{@{}@{\extracolsep{\fill}}rlrr
@{\extracolsep{6pt}}r@{\extracolsep{\fill}}r@{\extracolsep{0pt}}r
@{\extracolsep{\fill}}r@{\extracolsep{6pt}}r@{\extracolsep{\fill}}r
@{\extracolsep{0pt}}r@{\extracolsep{\fill}}c@{\extracolsep{0pt}}@{}}
\hline\hline
\multicolumn{1}{c}{HD}&\multicolumn{1}{c}{Ion}&\multicolumn{1}{c}{$n$}
&\multicolumn{1}{c}{$a_0$}&\multicolumn{1}{c}{$\sigma(a_0)$}
&\multicolumn{1}{c}{$a_1$}&\multicolumn{1}{c}{$\sigma(a_1)$}
&\multicolumn{1}{c}{$a_2$}&\multicolumn{1}{c}{$\sigma(a_2)$}
&\multicolumn{1}{c}{$a_3$}&\multicolumn{1}{c}{$\sigma(a_3)$}
&\multicolumn{1}{c}{$10^3~$rms}\\[1pt]
&&&\multicolumn{2}{c}{$[\mbox{\rm\AA}^2 ]$}
&\multicolumn{2}{c}{{$[({\rm km~s}^{-1})^2]$}}
&\multicolumn{2}{c}{$[{\rm G}^2]$}
&\multicolumn{2}{c}{{$[10^6~({\rm km}~{\rm s}^{-1}~
\mbox{\rm\AA}^{-1})^4 ]$}}
&\multicolumn{1}{c}{$[\mbox{\rm\AA}^2 ]$}\\[2mm]
\hline
 91375&\ion{Fe}{i} &122&$8.127\times10^{-4}$&$2.887\times10^{-4}$%
&73.12&  7.19&$2.761\times10^6$&$1.181\times10^6$& 5.776& 0.379& 0.662\\
      &\ion{Fe}{ii}& 58&$2.738\times10^{-3}$&$0.497\times10^{-3}$%
&76.79& 13.41&\llap{$-$}$3.250\times10^6$&$2.397\times10^6$& 3.287& 0.338& 0.924\\[1pt]
133792&\ion{Cr}{ii}& 83&$9.756\times10^{-4}$&$1.877\times10^{-4}$%
&19.86&  4.45&$2.103\times10^5$&$5.959\times10^5$& 2.289& 0.188& 0.444\\[1pt]
\hline
\end{tabular}
\end{table}