Donahue et al. present a very interesting and detailed study on how nucleation can be described within the previously established volatility basis set (VBS). In a first part, the thermodynamic principles of nucleation are introduced alongside a description of the VBS and subsequently extended to the nucleation of organic vapors. In the second part, the application of the VBS to nucleation is discussed in a general manner and applied in the following to previously published results from chamber nucleation experiments. The paper is well-written and follows a clear flow and logic. The presented method allows a more detailed investigation of the contribution of organic vapors to nucleation and might have substantial impact in the field.

I have some minor comments and suggestion to consider prior to publication.

• Caption Figure 1. The two panels are described as ‘a)’ and ‘b)’ which is not detailed on the plots.
• l. 107 The term ‘aerosol-phase activity’ is used here to explain decreased tendency of organic vapors to condense on very small particles, but is not well defined in this context. As I understand the reduced interaction with the particle surface due to the contribution of the particle curvature is the reason for this tendency, I suggest a brief introduction of the activity term.
• l. 147 The temperature dependency is introduced very briefly here, although it is the basis for large sections of the conclusions in this paper. I understand that this was largely introduced in the cited studies, but I would suggest adding a few more points on the assumptions necessary and maybe limitations of this approach. This might help to judge the robustness of the derived conclusions.
• l. 152 Here, the authors link nucleation with the saturation ratio of a mixture based on the VBS. The assumption being, that the formation of a cluster is driven by volatility alone and detailed chemical structure is statistically similar enough across the mixture of vapors. In section 3.3, the authors introduce a gain to describe nucleation efficiency, motivating it in part with different functional groups and the resulting different bonding situation. Is the chemical nature of a mixture and its influence on nucleation something that could be parametrized using the approach presented in this manuscript if enough comparable experimental datasets would be available?
• l. 231 should read ‘sensitive to the chemical identity’
• l. 368 the minimum is could as well be outside this window, above 278 K or below 263 K, right?
• More to that point, the measurements seem to have large uncertainties. Did the authors attempt to apply the temperature dependence to estimate the nucleation rate from the chemical composition experiments at another temperature? I understand this might inflate the manuscript too much, but maybe an example case could help to understand how different the chemical composition actually contributes to the nucleation rate.