\begin{table}%T1
%\centering
\par
\caption{$LS$ energies relative to the 2s$^2$2p~$^2$P$^{\rm o}$
ground state of \ion{C}{ii}. Also noted is how the $LS$ states split into $J$-levels and assignments of level indices to
the target states are given. The observed values are the experimental energy
levels compiled by NIST.}\label{table:energies} 
\begin{tabular}{lccccc}
\hline \hline 
$LS$ state&Present $LS$&Observed $LS$&No. split&$J$ level&Level\\
          &energy(Ry)  &energy(Ry)   &levels   &         &index\\[1mm] \hline \\[-3mm]
2s$^2$2p~$^2$P$^{\rm o}$&0.00000 & 0.00000 & 2 & 1/2 & 1\\
&&&&3/2&2\\
2s2p$^2$~$^4$P&0.38727&0.39179&3&1/2&3\\
&&&&3/2&4\\
&&&&5/2&5\\
2s2p$^2$~$^2$D&0.68854&0.68282&2&3/2&6\\
&&&&5/2&7\\
2s2p$^2$~$^2$S&0.88923&0.87893&1&1/2&8\\
2s2p$^2$~$^2$P&1.02281&1.00795&2&1/2&9\\
&&&&3/2&10\\
2s$^2$3s~$^2$S&1.06269&1.06158&1&1/2&11\\
2s$^2$3p~$^2$P$^{\rm o}$&1.19905&1.20004&2&1/2&12\\
&&&&3/2&13\\
2p$^3$~$^4$S$^{\rm o}$&1.29715&1.29386&1&3/2&14\\
2s$^2$3d~$^2$D&1.32693&1.32597&2&3/2&15\\
&&&&5/2&16\\
2p$^3$~$^2$D$^{\rm o}$&1.38334&1.37074&2&3/2&17\\
&&&&5/2&18\\
2s$^2$4s~$^2$S&1.43097&1.43244&1&1/2&19\\
2s$^2$4p~$^2$P$^{\rm o}$&1.48005&1.48063&2&1/2&20\\
&&&&3/2&21\\
2s2p($^3$P$^{\rm o}$)3s~$^4$P$^{\rm o}$&1.52144&1.52152&3&1/2&22\\
&&&&3/2&23\\
&&&&5/2&24\\
2s$^2$4d~$^2$D
&1.52981&1.53167&2&3/2&25\\
&&&&5/2&26\\
2p$^3$~$^2$P$^{\rm o}$&1.54761&1.53731&2&1/2&27\\
&&&&3/2&28\\
2s$^2$4f~$^2$F$^{\rm o}$
&1.53640&1.53946&2&5/2&29\\
&&&&7/2&30\\[1mm]
\hline
\end{tabular}
\end{table}