Summary of the results from our POSEIDON panchromatic equilibrium chemistry retrieval. The format of the upper two panels of this figure is identical to that of Figure 3, but the metallicity and C/O ratio are derived from the equilibrium chemistry grid rather than computed from molecule VMRs. We find HAT-P-1 b’s atmosphere to have a ﹩{\mathrm{log}}_{10}[{\rm{M}}/{\rm{H}}]=0.9{9}_{-0.14}^{+0.19}﹩, corresponding to approximately 10× solar or 9× the near-solar host-star metallicity, and a factor of at least 4 more oxygen than carbon. There is a notable discrepancy in the cloud-coverage fraction between the free and equilibrium POSEIDON retrievals; JWST NIRISS SOSS observations of HAT-P-1 b will help alleviate this tension in the future.