A recent study suggests the existence of highly polar and nonpolar long-ran
ge Rydberg molecules under temperature and density conditions representativ
e of those found in atomic Bose-Einstein condensates. The electronic wave f
unctions of these Rydberg molecules are characterized by an elliptically sh
aped nodal structure. We use a combination of quantum and semiclassical met
hods to explore this unique nodal structure and its correlations with the B
orn-Oppenheimer potential curves of the molecules. We demonstrate a special
"quasiseparability" that arises in elliptic coordinates at certain internu
clear separations and give a semiclassical interpretation of this in terms
of quantized Einstein-Brillouin-Keller orbits.