Simulated data: cross-correlation signal-to-noise ratio (S/N_CCF) K_p−V_rest maps of all tested species. Each row displays the map corresponding to a different species. The leftmost column displays the results obtained with a C/O ratio of 0.1, and an opaque cloud top pressure of 1.7 log₁₀(Pa). Going to the right, the columns display the results from cloudless (P_c = 7 log₁₀(Pa)) simulated datasets, with C/O ratio of 0.1, 0.55, and 0.8, respectively. Negative values indicate an anti-correlation of the template with the data. The vertical and horizontal dashed lines show the expected K_p of the planet and the 0 km·s⁻¹ rest velocity, respectively. The red cross indicates the location of the maximum S/N. Rest velocities lower than −100 km·s⁻¹ and larger than +100 km·s⁻¹ are not shown for clarity. The maximum S/N_CCF can be in this excluded region, hence the red cross is not on all figures. All simulated data use the same noise seed, hence random features are the same on different models.