The precession period, semi-major axis, and eccentricity of the disc gap vs. time, for our five different systems. Disc models on the left are calculated with PLUTO and disc models on the right are calculated with FARGO3D. The precession period, T_prec, in the first row is given in terms of the corresponding period number. The horizontal lines indicate the time average starting from 6000 binary orbits, roughly the time when the discs reached a quasi-steady state. See the text for an explanation of the meaning of the + and × signs in the first row.