  We study the coherent association of a two-species atomic condensate into a
condensate of heteronuclear diatomic molecules, using both a semiclassical
treatment and a quantum mechanical approach. The differences and connections
between the two approaches are examined. We show that, in this coupled
nonlinear atom-molecule system, the population difference between the two
atomic species plays a significant role in the ground-state stability
properties as well as in coherent population oscillation dynamics.
