Knowledge Bank

The $\nu 2=2$ bending vibrational levels in the $A~2\Pi$ and $X~2\Sigma +$ states of the CaOD radical have been rotationally analyzed via dye laser excitation of the $A~(100)/(020)-X~(020)/(000)$ bands. The near degeneracy between the $A~(100)2\Pi 1/2$ and $A~(020)2\Pi 3/2$ vibronic components makes it necessary to study the (100)-(020) Fermi diad simultaneously. A global fit of all the observed bands has been performed, employing an effective Hamiltonian that takes account of Renner-Teller, spin-orbit, Coriolis and Fermi resonance interactions occurring in the six $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi$ vibronic components. The Fermi resonance parameter for the CaOD $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi$ state has been determined as $W1=5.2293(24)cm-1$. Similar previous work for CaOH by the present authors led to the result $W1=10.3260(5)cm-1$.