Cumulative distribution of neighbouring planet pairs. Dashed curves show the situation after the end of the gas disc phase (t = 3 Myr), for both simulations suites runf3 (blue) and runf5 (orange). The full lines show the situation after 100 Myr of additional evolution. For the super-Earth systems most resonant pairs do not survive the post-gas phase. The vertical grey thin lines show the period ratios corresponding to, from left to right, the 5: 4, 4: 3, 3:2, 2:1 first-order mean-motion resonances. For comparison, the green short-dashed curve shows the observed period ratio distribution of the Kepler multi-planet systems, limited to a maximal period ratio of P_out ∕P_in = 4.