\begin{table}%t4
\par
\caption{\label{table:4}Metal bearing molecules in IRC+10216.} 
%\centerline
 {
\begin{tabular}{lcccc}
\noalign{\smallskip}
\hline
\hline
\noalign{\smallskip}
Species   & $\theta_{\rm r}$\tablefootmark{a}  & $X_{\rm {mol}}$\tablefootmark{b}  & $X_{\rm {mol}}/X_\odot$  & Ref.  \\
          &  (\arcsec)  \\
\noalign{\smallskip}
\hline
\noalign{\smallskip}
NaCl   &   2.5    &  1.3($-$09)  &  6.3($-$4)  &  1 \\
NaCN   &   2.5    &  6.8($-$09)  &  3.4($-$3)  &  1 \\
\noalign{\smallskip}
KCl    &    2.5   &  3.8($-$10)  &  2.9($-$3)  &  2 \\ 
\noalign{\smallskip}
AlF   &    2.5    &  4.6($-$08)  &  1.6($-2$) &  1  \\
AlCl  &    2.5    &  2.8($-$08)  &  9.8($-$3) &  1  \\
AlNC  &   5--15   &  2.3($-$10)  &  7.9($-$5) &  3  \\
\noalign{\smallskip}
MgNC  &   10--20  &  6.3($-$09)  & 1.8($-$4)  &  1  \\
MgCN  &   10--20  &  2.9($-$10)  & 8.0 ($-$6) &  4  \\
 \noalign{\smallskip}
 \hline
 \end{tabular}}
\par
\tablefoot {
\tablefoottext{a} {Source radius.}
\tablefoottext{b} {Abundance relative to H, for $d=120$~pc,  $\dot{M}({\rm H})=1.25 \times 10^{-5}$~$M_{\odot}$~yr$^{-1}$.}\vspace{-2mm}
\tablebib {(1) Highberger \& Ziurys\ (\cite{highberger03}). (2)
Assuming $X({\rm{KCl}}) = 0.3 X({\rm{NaCl}})$ Cernicharo \&
Gu\'elin (\cite{cernicharo87}). (3) Ziurys et~al.\
(\cite{ziurys02}). (4)~Assuming $X({\rm{MgCN}}) = 0.045 X({\rm{MgNC}})$ Ziurys et~al.\ (\cite{ziurys95}).   }}
\vspace{2mm}
\end{table}