\begin{table}%T1
%\centering
\par
\caption{Molecular ab~initio properties used in the calculations.}
\label{tab:ref}
\begin{tabular}{ll}
\hline
\hline
$Quantity$  & Reference \\
\hline
X~$^{1}\Sigma_{g}^{+}$ adiabatic potential  & \citet{wol93} \\
B~$^{1}\Sigma_{u}^{+}$ adiabatic potential  & \citet{stasz02}  \\
B$'$~$^{1}\Sigma_{u}^{+}$ adiabatic potential  & \citet{stasz02}  \\
C~$^{1}\Pi_{u}$ adiabatic potential  & \citet{wol03a}   \\
D~$^{1}\Pi_{u}$ adiabatic potential  & \citet{wol03a}   \\
Off-diagonal rotational and radial matrix elements &  \citet{wol88} \\
B--X transition moment& \citet{wol03b} \\
B$'$--X transition moment& \citet{wol03b} \\
\hline
\end{tabular}
\end{table}