MECHANISM OF EXTERNAL MAGNETIC-FIELD DEPENDENT FLUORESCENCE DECAYS OF GASEOUS CARBON-DISULFIDE

Mechanisms of the external magnetic field dependent fluorescence decays of gaseous molecules are theoretically investigated with particular attention being paid to the Renner-Teller effect in linear molecules. A nonradiative decay rate constant including both the Zeeman and intramolecular nonadiabatic interactions bas been expressed in the time-independent Green's function formalism. A reduced form for the electronic Zeeman interaction matrix element between the Renner-Teller coupled rovibronic states has been derived. Applying this formalism to CS2, we find that its field dependent ultrafast fluorescence decay may be explained qualitatively by an external magnetic field-induced nonradiative transition between the Renner-Teller components. The fluorescence intensity depletion from the 1A2 state Of CS2 in the presence of an external magnetic field may also be explained by a field-induced nonradiative transition.