\begin{table}%t3
\caption{\label{param}Variational ranges of the parameters.}
%\centering
\par
\begin{tabular}{lll}
\hline \hline \noalign{\smallskip}
Parameter & Range & N runs \\
\hline
Reaction rate coefficients & Uncertainty Factor & 2500 \\
Temperature\tablefootmark{*} & 5$-$15 K & 2500 \\
H density\tablefootmark{*} & $(1{-}3) \times 10^{4}$ cm$^{-3}$  & ---  \\
Elemental abundances &  $\pm$50\% & 2000 \\
Cosmic-ray ionization rate ($\zeta$) & $(0.5{-}5.0) \times 10^{-17}$ s$^{-1}$  & 1000 \\
Initial Concentrations & see text & 3500 \\
\hline
\end{tabular}
\tablefoot {\tablefoottext{*}{Varied together.}}
\end{table}