\begin{table}%T2
\caption{ Lowest 66 energy levels in Ry for the $n=4$ calculation compared to 
          experimental measurements listed on NIST ({\tt http://physics.nist.gov}).}
\label{tab2}
%\centering
\par
\begin{tabular}{ c c c c | c c c c | c c c c }
\hline\hline
$i$  & Level                                & Present   & NIST     &  $i$  & Level                               & Present   & NIST     &  $i$  & Level                                  & Present  & NIST     \\
\hline
1  & 2p$^5$ $^2$P$^{{\rm o}}_{3/2}$      & 0.0       & 0.0      &  23 & 2p$^4$ 3p $^2$S$^{{\rm o}}_{1/2}$  & 60.309    & 	        &  45 & 2p$^4$ 3d $^4$F$_{7/2}$                & 63.111   &          \\   
2  & 2p$^5$ $^2$P$^o_{1/2}$               & 0.955     & 0.935    &  24 & 2p$^4$ 3p $^2$D$^{{\rm o}}_{3/2}$  & 60.356    & 	        &  46 & 2p$^4$ 3d $^2$D$_{3/2}$                & 63.140   &          \\  
3  & 2s 2p$^6$ $^2$S$_{1/2}$              & 9.830     & 9.702    &  25 & 2p$^4$ 3p $^2$F$^{{\rm o}}_{5/2}$  & 60.693    & 	        &  47 & 2p$^4$ 3d $^4$P$_{5/2}$                & 63.297   & 62.911   \\
4  & 2p$^4$ 3s $^4$P$_{5/2}$              & 56.798    & 56.699   &  26 & 2p$^4$ 3p $^2$F$^{{\rm o}}_{7/2}$  & 60.878    &          &  48 & 2p$^4$ 3d $^2$P$_{3/2}$                & 63.418   & 63.308   \\
5  & 2p$^4$ 3s $^2$P$_{3/2}$              & 57.052    & 56.937   &  27 & 2p$^4$ 3p $^2$D$^{{\rm o}}_{3/2}$  & 61.016    & 	        &  49 & 2p$^4$ 3d $^2$D$_{5/2}$                & 63.516   & 63.401   \\
6  & 2p$^4$ 3s $^4$P$_{1/2}$              & 57.492    & 57.503   &  28 & 2p$^4$ 3p $^2$D$^{{\rm o}}_{5/2}$  & 61.126    & 	        &  50 & 2p$^4$ 3d $^2$G$_{7/2}$                & 63.787   &          \\
7  & 2p$^4$ 3s $^4$P$_{3/2}$              & 57.664    & 57.573   &  29 & 2p$^4$ 3p $^2$P$^{{\rm o}}_{3/2}$  & 61.590    & 	        &  51 & 2p$^4$ 3d $^2$G$_{9/2}$                & 63.825   &          \\
8  & 2p$^4$ 3s $^2$P$_{1/2}$              & 57.899    & 57.798   &  30 & 2p$^4$ 3p $^2$P$^{{\rm o}}_{1/2}$  & 61.758    & 	        &  52 & 2p$^4$ 3d $^2$F$_{5/2}$                & 64.052   &          \\
9  & 2p$^4$ 3s $^2$D$_{5/2}$              & 58.444    & 58.321   &  31 & 2p$^4$ 3d $^4$D$_{5/2}$             & 62.114    & 	        &  53 & 2p$^4$ 3d $^2$S$_{1/2}$                & 64.056   & 63.919   \\
10 & 2p$^4$ 3s $^2$D$_{3/2}$              & 58.478    & 58.356   &  32 & 2p$^4$ 3d $^4$D$_{7/2}$             & 62.127    & 	        &  54 & 2p$^4$ 3d $^2$F$_{7/2}$                & 64.156   &          \\
11 & 2p$^4$ 3p $^4$P$^{{\rm o}}_{3/2}$   & 59.019    &          &  33 & 2p$^4$ 3d $^4$D$_{3/2}$             & 62.157    & 63.051   &  55 & 2p$^4$ 3d $^2$P$_{3/2}$                & 64.280   & 64.139   \\
12 & 2p$^4$ 3p $^4$P$^{{\rm o}}_{5/2}$   & 59.053    &          &  34 & 2p$^4$ 3d $^4$D$_{1/2}$             & 62.247    & 62.907   &  56 & 2p$^4$ 3d $^2$D$_{5/2}$                & 64.335   & 64.160   \\
13 & 2p$^4$ 3p $^4$P$^{{\rm o}}_{1/2}$   & 59.296    &          &  35 & 2p$^4$ 3p $^2$P$^{{\rm o}}_{3/2}$  & 62.335    & 	        &  57 & 2p$^4$ 3d $^2$D$_{3/2}$                & 64.558   & 64.391   \\
14 & 2p$^4$ 3p $^4$D$^{{\rm o}}_{7/2}$   & 59.350    &          &  36 & 2p$^4$ 3d $^4$F$_{9/2}$             & 62.356    & 	        &  58 & 2p$^4$ 3d $^2$P$_{1/2}$                & 64.623   & 64.465   \\
15 & 2p$^4$ 3p $^2$D$^{{\rm o}}_{5/2}$   & 59.365    &          &  37 & 2p$^4$ 3d $^2$F$_{7/2}$             & 62.452    & 	        &  59 & 2p$^4$ 3d $^2$D$_{5/2}$                & 65.356   & 65.305   \\
16 & 2p$^4$ 3s $^2$S$_{1/2}$              & 59.807    & 59.917   &  38 & 2p$^4$ 3p $^2$P$^{{\rm o}}_{1/2}$  & 62.542    & 	        &  60 & 2s2p$^5$ 3s $^4$P$^{{\rm o}}_{5/2}$   & 65.396   & 65.482   \\
17 & 2p$^4$ 3p $^4$D$^{{\rm o}}_{1/2}$   & 59.810    &          &  39 & 2p$^4$ 3d $^4$P$_{1/2}$             & 62.597    & 62.497   &  61 & 2p$^4$ 3d $^2$D$_{3/2}$                & 65.542   & 65.468   \\
18 & 2p$^4$ 3p $^4$D$^{{\rm o}}_{3/2}$   & 59.840    &          &  40 & 2p$^4$ 3d $^4$P$_{3/2}$             & 62.734    & 62.626   &  62 & 2s 2p$^5$ 3s $^4$P$^{{\rm o}}_{3/2}$  & 65.726   & 65.591   \\
19 & 2p$^4$ 3p $^2$P$^{{\rm o}}_{1/2}$   & 59.844    &          &  41 & 2p$^4$ 3d $^2$F$_{5/2}$             & 62.816    & 62.699   &  63 & 2s 2p$^5$ 3s $^4$P$^{{\rm o}}_{1/2}$  & 66.140   & 65.835   \\
20 & 2p$^4$ 3p $^2$P$^{{\rm o}}_{3/2}$   & 59.980    &          &  42 & 2p$^4$ 3d $^2$P$_{1/2}$             & 62.957    &          &  64 & 2s 2p$^5$ 3s $^2$P$^{{\rm o}}_{3/2}$  & 66.221   & 66.075   \\
21 & 2p$^4$ 3p $^4$D$^{{\rm o}}_{5/2}$   & 60.124    &          &  43 & 2p$^4$ 3d $^4$F$_{3/2}$             & 62.989    &          &  65 & 2s 2p$^5$ 3s $^2$P$^{{\rm o}}_{1/2}$  & 66.709   &          \\
22 & 2p$^4$ 3p $^4$S$^{{\rm o}}_{3/2}$	  & 60.157    &          &  44 & 2p$^4$ 3d $^4$F$_{5/2}$             & 63.012    &	         &  66 & 2s 2p$^5$ 3p $^4$S$_{3/2}$             & 67.505   &          \\
\hline
\end{tabular}
\end{table}