Result of the stability analysis of 80 000 six-planet solutions in the plane of initial semi-major axis a vs. initial mean longitude λ obtained from a numerical integration over T ≈ 7000 years. Each initial condition is represented as a point. Initial conditions leading to an immediate disintegration of the system are shown as gray dots. Initial conditions that lead to stable motion for at least 1 Myr are shown as red points (D < 10^-5). Black crosses represent the most stable solutions (D < 10^-6), and can last over many Myr.