\begin{table}%t1
\caption {\label{tab:Species}Elements and chemical species.}
%\centerline
 {\begin{tabular}{cp{6.6cm}}
\hline \hline
 9 elements & H, He, C, N, O, Mg, Si, S, Fe\\
\hline 
 71 species & H, H$^+$, H$^-$,
He, He$^+$, C, C$^+$, O, O$^+$, S, S$^+$, Si, Si$^+$, Mg, Mg$^+$, Fe,
Fe$^+$, N, N$^+$, H$_2$, H$_2^+$, H$_2^\star$, H$_3^+$, OH, OH$^+$,
H$_3$O$^+$, H$_2$O, H$_2$O$^+$, CO, CO$^+$, HCO, H$_2$CO, HCO$^+$,
O$_2$, O$_2^+$, CO$_2$, CO$_2^+$, CH, CH$^+$, CH$_2$, CH$_2^+$,
CH$_3$, CH$_3^+$, CH$_4$, CH$_4^+$, CH$_5^+$, SiO, SiO$^+$, SiH,
SiH$^+$, SiH$_2^+$, SiOH$^+$, NH, NH$^+$, NH$_2$, NH$_2^+$, NH$_3$,
NH$_3^+$, N$_2$, HN$_2^+$, CN, CN$^+$, HCN, HCN$^+$, NO, NO$^+$, CO\#,
H$_2$O\#, CO$_2$\#, CH$_4$\#, NH$_3$\#\\
\hline 
\end{tabular}}
\smallskip
Ice species are denoted with ``\#''.\\
H$_2^\star$ designates vibrationally excited H$_2$.
\end{table}