Predicted trend of how atmospheric C/O values change as a function of atmospheric mass assuming a planet mass of 10 M_⊕, bulk ratios for C/O = 0.01 (dashed line) and O/Si = 3.3 (Earth-like), and a 3000 K magma ocean surface. Higher atmospheric C/O is predicted for TOI-5817 b than for TOI-5800 b, given their different inferred atmospheric mass fractions (solid grey lines; errors are large and not shown).