\begin{table}%t1
\caption{\label{table1}Configurations included in various expansions used for \ion{Si}{ii}.} 
%\centering
\small
\begin{tabular}{ll}
\hline\hline \noalign{\smallskip}
CE1 &
2s$^2$2p$^6$3s$^2$3p, 2s$^2$2p$^6$3s3p$^2$, 2s$^2$2p$^6$3s3p3d,\\
& 2s$^2$2p$^6$3s3d$^2$, 
 2s$^2$2p$^6$3p$^3$, 
2s$^2$2p$^6$3p$^2$3d, \\
& 2s$^2$2p$^6$3p3d$^2$, 2s$^2$2p$^6$3d$^3$,
 2s$^2$2p$^6$3s$^2$3d, \\ 
& 2s$^2$2p$^6$3s$^2$4s, 
2s$^2$2p$^6$3s$^2$4p,
2s$^2$2p$^6$3s$^2$4d,\\
& 2s$^2$2p$^6$3s$^2$5s, 2s$^2$2p$^6$3s$^2$5p,
2s$^2$2p$^6$3s$^2$5d, \\
&2s$^2$2p$^6$3s3p4s,
2s$^2$2p$^6$3s3p4p,   2s$^2$2p$^6$3s3d4p, \\
&  2s$^2$2p$^6$3s3d4d,
2s$^2$2p$^6$3s4p$^2$, 
 2s$^2$2p$^6$3s4s5s,\\
& 2s$^2$2p$^6$3p$^2$4s, 2s$^2$2p$^6$3p3d4p,   2s$^2$2p$^6$3d$^2$4s\\
\hline\noalign{\smallskip}
CE2 & 2s$^2$2p$^6$3s$^2$4f,  2s$^2$2p$^6$3s$^2$5f\\
\hline\noalign{\smallskip}
CE3 & 2s$^2$2p$^5$3s$^2$3p$^2$, 2s$^2$2p$^5$3s$^2$3p3d,
2s$^2$2p$^5$3s$^2$3p4s\\
\hline\noalign{\smallskip}
CE4 &2s$^2$3p$^4$3s$^2$3p$^3$, 2s$^2$2p$^4$3s$^2$3p$^2$3d,
2s$^2$2p$^4$3s$^2$3p$^2$4s \\
\hline\noalign{\smallskip}
CE5  & 2s2p$^6$3s$^2$3p$^2$, 2s2p$^6$3s$^2$3p3d, 2s2p$^6$3s$^2$3p4s \\
\hline\noalign{\smallskip}
CE6 &2s$^2$2p$^5$3s$^2$3p4p, 2s$^2$2p$^5$3s$^2$3p4d,
2s$^2$2p$^4$3s$^2$3p$^2$4p, \\ 
& 2s$^2$2p$^4$3s$^2$3p$^2$4d, 
2s$^2$2p$^3$3s$^2$3p$^4$, 2s$^2$2p$^3$3s$^2$3p$^3$3d, \\ 
& 2s$^2$2p$^3$3s$^2$3p$^3$4s, 2s$^2$2p$^3$3s$^2$3p$^3$4p,
 2s$^2$2p$^3$3s$^2$3p$^3$4d \\
\hline
\end{tabular}
\end{table}