Precession period for GRS 1758–258 as a function of the spin parameter. The outer non-dimensional radius of the disc is taken to be ξ_out = 1000ξ_ms. Different lines correspond to the different power-law slopes of the disc surface density (red-continuous for s = 0; blue-dashed for s = −1, and black-dotted for s = −2). The grey-dotted horizontal line marks the estimated period of precession of approximately 7.5 yr, while the magenta-dotted line marks the 18.48 days precession period proposed in Martí et al. (2016).