Knowledge Bank

The predissociation In the $A2\Sigma +$ state of CF and the results of MCSCF calculations of the low lying CF electronic states have been described at previous $symposia.1,2$ The width of the $A2\Sigma +$-X$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi$ (2,0) lines increases rapidly with rotational quantum number, $N\prime >35$. The ab initio potential for the predissociating state, $a4\Sigma -$, develops a barrier with a maximum near 3.5 $a0$. We have calculated the vibrational overlap matrix elements for scaled potentials representing the $A2\Sigma +$ and $a4\Sigma -$ states. The line width pattern calculated from these matrix elements is consistent with the observed pattern. The influence of vibrational-rotational (shape) resonances of the $a4\Sigma -$ state on the line width pattern will be discussed.