**Table 3:** Line parameters.
$\begin{table} \par \begin{displaymath} \begin{array}{rrrrr} \hline\hline \no... ...skip } \hline \noalign{\smallskip } \end{array} \end{displaymath} \end{table}$

^a Line data taken from the NIST database.
$^{{\rm b}}$ From Thorén et al. in preparation.
^c From Thorén & Feltzing (2000).