\begin{table}%t2
%\centering
\par
\caption {\label{fe_z}Transformation of [Fe/H] to [$Z$].}
\begin{tabular}{cccccc}
\hline \hline \noalign{\smallskip}
[Fe/H] & [$Z$] & [Fe/H] & [$Z$] & [Fe/H] & [$Z$] \\
\hline
$-$0.729 & 0.004 & $-$0.030 & 0.018 & +0.253 & 0.032 \\ 
$-$0.525 & 0.006 & +0.019 & 0.020 & +0.288 & 0.034 \\
$-$0.387 & 0.008 & +0.077 & 0.022 & +0.312 & 0.036 \\
$-$0.282 & 0.010 & +0.116 & 0.024 & +0.343 & 0.038 \\
$-$0.224 & 0.012 & +0.152 & 0.026 & +0.371 & 0.040 \\
$-$0.149 & 0.014 & +0.185 & 0.028 \\
$-$0.086 & 0.016 & +0.225 & 0.030 \\
\hline
\end{tabular}
\end{table}