WEAK-FIELD AND STRONG-FIELD STARK ENERGY-LEVELS OF SYMMETRICAL-TOP DIPOLAR MOLECULES

Perturbation expansions of the energy levels of symmetric top dipolar molecules in weak and strong electric fields (field strength F) are ex tended up to terms proportional to F3 (for weak fields) and to F-1 (fo r strong fields). For small quantum numbers, suitable analytical inter polations between the weak- and strong-field expansions are obtained f rom matrix diagonalization results. For large quantum numbers, where t his approach becomes inconvenient, quasiclassical techniques provide t hese interpolations. The expressions are of use not only in spectrosco py but also in reaction kinetics, e.g., in adiabatic channel treatment s of reactions on attractive potentials with cos theta anisotropies.