\begin{table}%t1
%\centering
\par
\caption{Comparison of the interaction constant from this work
and computed with the  collisional broadening theory of Anstee et~al. (\cite{Anstee97}).}\label{t1}
\begin{tabular}{llllll}
\hline
\hline
\noalign{\smallskip}
${\rm Species}$ & ${\rm \lambda ( \AA )}$ & ${\rm \chi_{ex}}$ (eV) &
 $\log\; gf$
 & ${C_6^{\rm present}}$
 & ${C_6^{\rm AOR97}}$   \\
\noalign{\smallskip}
\hline
\noalign{\smallskip}
Mg I & 5167.321 & 2.709   & $-$0.857 & 0.8E--31 & 0.29E--30  \\
Mg I & 5172.684 & 2.712   & $-$0.38 & 0.8E--31 & 0.29E--30  \\
Mg I & 5183.604 & 2.717   & $-$0.158 & 0.1E--30 & 0.29E--30  \\
Fe I & 5227.192 & 1.56   & $-$1.5 & 0.4E--31 & 0.29E--31  \\
Fe I & 5269.550 & 0.86   & $-$1.32 & 0.6E--32 & 0.18E--31  \\
Fe I & 5328.051 & 0.91   & $-$1.666 & 0.8E--32 & 0.19E--31  \\
Fe I & 5328.542 & 1.56   & $-$2.15 & 0.8E--31 & 0.28E--31  \\
Fe I & 5397.141 & 0.91   & $-$1.993 & 0.2E--31 & 0.19E--31  \\
Fe I & 5446.924 & 0.91   & $-$2.55  & 0.7E--31 & 0.19E--31  \\
\noalign{\smallskip} 
\hline 
\end{tabular}
\end{table}