Free-volume model for the diffusion coefficients of solutes at infinite dilution in supercritical CO2 and liquid H2O

► New free-volume model for tracer diffusion coefficients in SC-CO2 and liquid water. ► Validation accomplished with a large database: 289 systems with 5485 data points. ► Database includes extremely distinct molecules in terms of size, polarity and symmetry. ► Global deviations are only 3.56% for correlation and 3.73% for prediction. ► A spreadsheet for the calculation of diffusivities is given in Supplementary data.