Figure 4.

Activation free energy as a function of pressure. ΔW_u^‡ and ΔW_f^‡ are the free energy differences of the contact (□) and solvent-separated minima (▪), respectively, to the desolvation barrier of the pmf for methane association (Fig. 2). Activation volumes Δv_u^‡ and Δv_f^‡ are derived from a linear fit for pressures between 0 and 500 MPa.