In Figure , the key features 72 and 74 of the HBD and HBA molecules are shown to be the most critical, negatively impacting the model. The DESs mixtures containing these features in the HBD and HBA have an average CO 2 solubility of -4.4856 ± 0.8870. For these mixtures, the pressure goes from 46.9 to 6323 kPa and the temperature from 293.15 to 348.15 K. These results suggest that combining these molecules requires high pressure to achieve higher solubilities. The HBA molecules that con-tain feature 74 are Tetramethylammonium chloride, Tetramethylammonium chloride, N-Benzyl-2hydroxy-N, N-dimethyl ethanaminium chloride, Choline chloride, Benzyltrimethylammonium chloride, and Betain, Lactic acid, Furfuryl alcohol, Guaiacol, Ethylene glycol, 2,3-butanediol, Diethylene glycol, Glycerol, 1,2-propanediol, Triethyleneglycol, and 1,2-butanediol are the HBD molecules that contain the key feature 72. Feature 128 for HBA and HBD molecules is essential to improve the model response. For such DESs mixtures have an average CO 2 solubility of -2.5523 ± 0.8085. The maximum experimental pressure measured is 1990 and the lowest is 90.0 kPa. The temperature range goes from 298.15 to 333.15 K. These findings suggest that the DESs containing feature 128, either in HBA or HBD, require less pressure to achieve a higher solubility. HBA molecules that contain feature 128 are the Tetraoctylammonium chloride/bromide, Trioctylmethylammonium chloride/bromide, Tetrabutylammonium chloride/bromide, and Tetrabutylphosphonium bromide. Feature 129 contained in both molecules also has an important impact on the predicted solubility. The HBA molecules found tracking this feature do not differ from those found with feature 128. Hexanoic acid, diethanolamine, Decanoic acid, methyldiethanol amine, and diethylene glycol are the HBD molecules found containing this feature. The average solubility of the DESs containing feature 129 is -2.5846 ± 0.7368, obtained mainly at low pressures. The molecules found tracking the most important features in HBAs agree with those found by , where large alkyl chains are preferred for CO 2 capture.