The Soave Redlich Kwong equation of state was written by Giorgio Soave and published in Chemical Engineering Science, 1972, 27, pp 1197-1203 as Equilibrium constants from a modified Redlich - Kwong equation of state.
Mixing Rules

Parameters

Pure component fugacity

Mixture fugacities

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All this is fine, but you must specify the units, since there are constant factors that take up different values according to the units used.