\begin{table}%t1
\caption{Energy levels (in Ryd) of Fe {\sc xxvi}.}\label{tab1}
%\vspace*{-2mm}
\small %\centerline
 {\begin{tabular}{rllrrrrrr}
\hline\hline\noalign{\smallskip}
Index  & Configuration & Level  &  NIST      &  AS$^a$    &  GRASP$^b$ &  GRASP$^c$  &  GRASP$^d$   & FAC$^e$    \\
\hline\noalign{\smallskip}
 1 & 1s  & $^2$S$_{1/2}$        &    0.00000 &    0.00000 &    0.00000 &     0.00000 &      0.00000 &	   0.0000 \\
 2 & 2s  & $^2$S$_{1/2}$        &  511.00120 &  511.22287 &  510.99499 &   511.25775 &    511.00986 &	 511.0338 \\
 3 & 2p  & $^2$P$^\circ$$_{1/2}$    &  510.95974 &  511.21310 &  510.95198 &   511.25775 &    510.96906 &	 510.9933 \\   
 4 & 2p  & $^2$P$^\circ$$_{3/2}$    &  512.51892 &  512.73395 &  512.51098 &   512.81372 &    512.52826 &	 512.5526 \\
 5 & 3p  & $^2$P$^\circ$$_{1/2}$    &  606.09866 &  606.33270 &  606.09088 &   606.39679 &    606.10883 &	 606.1371 \\
 6 & 3s  & $^2$S$_{1/2}$        &  606.11160 &  606.34399 &  606.10384 &   606.39679 &    606.12097 &	 606.1492 \\
 7 & 3d  & $^2$D$_{3/2}$        &  606.56003 &  606.78235 &  606.55231 &   606.85815 &    606.57056 &	 606.5986 \\
 8 & 3p  & $^2$P$^\circ$$_{3/2}$    &  606.56095 &  606.78339 &  606.55314 &   606.85815 &    606.57117 &	 606.5994 \\
 9 & 3d  & $^2$D$_{5/2}$        &  606.71158 &  606.93256 &  606.70381 &   607.00928 &    606.72168 &	 606.7499 \\
10 & 4p  & $^2$P$^\circ$$_{1/2}$    &  639.33370 &  639.56219 &  639.32572 &   639.63177 &    639.34406 &	 639.3737 \\
11 & 4s  & $^2$S $_{1/2}$       &  639.33918 &  639.57025 &  639.33120 &   639.63177 &    639.34918 &	 639.3788 \\
12 & 4d  & $^2$D$_{3/2}$        &  639.52821 &  639.75043 &  639.52024 &   639.82629 &    639.53870 &	 639.5682 \\
13 & 4p  & $^2$P$^\circ$$_{3/2}$    &  639.52831 &  639.75232 &  639.52059 &   639.82629 &    639.53894 &	 639.5685 \\
14 & 4d  & $^2$D$_{5/2}$        &  639.59192 &  639.81378 &  639.58420 &   639.89008 &    639.60248 &	 639.6321 \\
15 & 4f  & $^2$F$^\circ$$_{5/2}$    &  639.59206 &  639.81366 &  639.58408 &   639.89008 &    639.60248 &	 639.6321 \\
16 & 4f  & $^2$F$^\circ$$_{7/2}$    &  639.62372 &  639.84534 &  639.61593 &   639.92188 &    639.63428 &	 639.6639 \\
17 & 5p  & $^2$P$^\circ$$_{1/2}$    &  654.68953 &  654.91608 &  .....     &   654.98773 &    654.70007 &	 654.7303 \\
18 & 5s  & $^2$S$_{1/2}$        &  654.69234 &  654.92236 &  .....     &   654.98773 &    654.70270 &	 654.7330 \\
19 & 5p  & $^2$P$^\circ$$_{3/2}$    &  654.78903 &  655.01343 &  .....     &   655.08722 &    654.79974 &	 654.8300 \\
20 & 5d  & $^2$D$_{3/2}$        &  654.78903 &  655.01135 &  .....     &   655.08722 &    654.79962 &	 654.8298 \\
21 & 5f  & $^2$F$^\circ$$_{5/2}$    &  654.82173 &  655.04352 &  .....     &   655.11993 &    654.83228 &	 654.8625 \\
22 & 5d  & $^2$D$_{5/2}$        &  654.82156 &  655.04382 &  .....     &   655.11993 &    654.83228 &	 654.8625 \\
23 & 5g  & $^2$G$_{7/2}$        &  654.83802 &  655.05969 &  .....     &   655.13617 &    654.84857 &	 654.8788 \\
24 & 5f  & $^2$F$^\circ$$_{7/2}$    &  654.83787 &  655.05975 &  .....     &   655.13617 &    654.84857 &	 654.8788 \\
25 & 5g  & $^2$G$_{9/2}$        &  654.84778 &  655.06940 &  .....     &   655.14594 &    654.85834 &	 654.8885 \\
\hline
\end{tabular}}
\medskip
NIST: \url { http://physics.nist.gov/PhysRefData}. \\
$^a$  Ballance et~al. (\cite{bbb02});\\
$^b$  Kisielius et~al. (\cite{kbn96});\\  
$^c$  Coulomb energies;\\
$^d$  QED corrected energies;\\  
$^e$  Energies calculated from the FAC code.  
\end{table}