Corner plot of the posteriors of the internal structure parameters of TOI-561 b. Shown are the mass fractions with respect to the solid planet of the inner core and water layer, the molar fractions of Si and Mg in the mantle layer and Fe in the inner core and the gas mass in Earth masses in a logarithmic scale. The labels at the top of each column are the median and the 5th and 95th percentiles of each distribution, which are also shown by the dashed lines.