\begin{table}%t1
%\centering
\par
\caption{Rate coefficients applied for the Oppenheimer \& 
Dalgarno model. The values are always used as reference values.}
%\begin{center}
\par
\begin{tabular}{lll}\hline\hline\noalign{\smallskip}
$\zeta$ & $\zeta_{{\rm eff}}^{}$ & $\rm s^{-1}_{}$\\
$\tilde{\alpha}$ & $3 \times 10^{-6}_{}/\! \sqrt{T}$ & $\rm cm^3_{} \ s^{-1}_{}$  \\
$\tilde{\beta}$  & $3 \times 10^{-9}_{}$ & $\rm cm^3_{} \ s^{-1}_{}$\\
$\tilde{\gamma}$ & $3 \times 10^{-11}_{}/\! \sqrt{T}$ &$ \rm cm^3_{} \ s^{-1}_{}$  \\ 
\hline          
\end{tabular}
%\end{center}
\par
\label{rates:oppenheimer}
\end{table}