Effects of spin-orbit coupling on the coupled 33Î and 43Î excited states of NaK

Spin-orbit coupling constants calculated for several excited states of the NaK molecule are used to interpret recent experiments. The theoretical results, which provide coupling constants as a function of internuclear separation R, were convoluted with vibrational wavefunctions in order to determine vibrational-state-dependent spectroscopic constants that could be compared with recent measurements for the 33Π state. Sharp structure in the experimental data could be attributed to rapid changes in the adiabatic spin-orbit coupling near an avoided crossing.