\begin{table}%t2
%\centering
\par
\caption{\label{tab:species} Chemical species considered in the
present inner wind model: elements are He, H, O, C, N, Si, and S.}\small
\begin{tabular}{ll}
\hline
\hline
O-bearing & O$_2$, O$_3$, OH, H$_2$O, CO, CO$_2$, \\
 & HCO, H$_2$CO, SiO, SiO$_2$, SO, SO$_2$, \\
 & SO$_3$, OCS, NO, HNO, N$_2$O, NO$_2$,\\
 & NO$_3$, OCN, HNCO, HO$_2$, H$_2$O$_2$. \\
\hline
C-bearing & C$_2$, C$_3$, CH, CH$_2$, CH$_3$, CH$_4$, \\
 & C$_2$H, C$_2$H$_2$, C$_3$H, C$_3$H$_2$, C$_4$H, C$_4$H$_2$, \\
 & CN, HCN, CS, HCS, HCSi, SiC, \\
 & SiC$_2$, SiCH$_2$. \\
\hline
Others & H$_2$, S$_2$, Si$_2$, Si$_3$, N$_2$, SiS, \\
 & HS, H$_2$S, SiH, SiH$_2$, SiH$_3$, SiH$_4$, \\
 & SiN, HNSi, NH, NH$_2$, NH$_3$, NS. \\
\hline
\end{tabular}
\end{table}