Chaotic phase space structure for a two-planet system with the same parameters as in the middle panel of Figure 6. Different colored curves show the predictions of different stability criteria (see text). The gray curve shows orbit-crossing eccentricity values. Note that the background grid of white and black points are plotted at their initial ﹩P/P^{\prime} ﹩ and e. That is why the black resonant tongues toward the right of the figure do not line up with the nominal positions of the first-order MMR’s. (They do line up when we plot mean, rather than initial, orbital elements.) The resonance-overlap predictions have been corrected to account for the difference between the osculating and mean period ratio using a correction accounting for 0th order resonances.