Knowledge Bank

The results of a theoretical calculation of the spectra associated with the laser induced fluorescence $A~2A1\to X~2E$ of both the methoxy molecule and CH$2$DO are presented and discussed. The form of the vibronic dipole moment is determined by symmetry and the corresponding dipole expansion coefficients are calculated using {\it ab initio} methods. The calculated spectra include states up to 3000 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$ above the zero point energy. We describe how the various features of the spectrum are related to coordinate dependent terms in the dipole expansion as well as the spin-orbit couplings, Jahn-Teller couplings, and vibrational anharmonicities.