\begin{table}%t1
\caption{\label{tab_rotcst}Rotation (B) and centrifugal distortion (D) constants for \ndhpb and \nddp, with errors in parentheses given for the last two digits.}
%\centering
\par
\begin{tabular}{ccc}
\hline \hline
Species&B&D\\
&MHz&MHz\\
\hline
\ndhp& 46586.8713(25)&0.08796(24) \\
\nddp& 38554.7479(17)&0.06181(15)\\
\hline
\end{tabular}
\end{table}