Top panel: surface density of the model in the xy plane in arbitrary units. The white star indicates the position of the Sun. The bar semi-major axis has an angle of 30 deg with respect to the Sun-Galactic centre line. The dashed lines indicate l = ±15 and l = ±30 angles. The solid white lines indicate 4 and 12 kpc distance from the Sun. The green circle delineates a radius of 6 kpc, which we refer to as the inner disc of the model. Bottom panel: edge-on view of the model in galactic longitude l and latitude b.