Transition sequence and birhythmicity in a chemical oscillation model showing chaos

Using a chemical oscillation model, a transition sequence in a chaotic region was studied in detail, and its fine structure in the vicinity of a critical point where a simple oscillation with a small amplitude becomes unstable and diverges to a new oscillatory state was reported. Neither a combined complex oscillation nor a chaotic oscillation appears between the two complex oscillations in this region, contrary to other cases reported already. Moreover, coexistence of a complex oscillation and a simple oscillation with a small amplitude was found to appear.