Body-fixed complex-coordinate coupled-channel formalism for rotational predissociation of van der Waals molecules

The method of complex-coordinate coupled-channel (CCCC) formalism previously developed in the space-fixed (SF) frame is reformulated in the body-fixed (BF) frame, more appropriate for strong-coupling van der Waals complexes. The utility of the method is demonstrated through a study of the level widths and energies of rotationally predissociating atom-diatom model systems. The possible usefulness of incorporating the centrifugal decoupling approximation in the BF CCCC theory is pointed out.