4. For the "C" molecule the following millimeter wave pure rotationat transitions has heen ofserwed (in \( \mathrm{MHz} \) ):
\begin{tabular}{|c|c|c|c|}
\hline Thananthen & \( v=0 \) & \( y-1 \) & \( y=-2 \) \\
\hline\( y=-0 \) & stakn & \( 48\left(673 m^{m}\right. \) & \( 48,280,887 \) \\
\hline\( x=2-\infty \) & \( 9, a m, 9 \times 0 \) & \( 97.2700 x 3 \) & \( 8,5600,30 \) \\
\hline \( 4-3-2 \) & \( 14 n+3 n \) & 145.84 867 & \( 144,818,826 \) \\
\hline\( L=x \) & 18, & 14433431 & 103,113959 \\
\hline
\end{tabular}
\[
A-A-B
\]
(a) For each vbrational level derive set of rotational constants by ftting the data.
(b) From the results of (a) derve an expression (by fiting) for the vibrational dependence of \( B \).
(c) From \( B_{s} \) calculate \( r_{s} \), from \( D_{e} \) calculate \( r_{e} \)
