Abstract Malijevský, A., Majer, V., Vondrák, P. and Tekáč, V., 1986. A semi-theoretical correlation of second virial coefficients. Fluid Phase Equilibria, 28: 283–308. Second virial coefficients were correlated simultaneously with low-density residual heat capacity (difference between heat capacities of real and ideal gases) by means of a three-parameter relation based on the Lennard-Jones potential with temperature dependent parameter σ. The relation was applied to 109 compounds, mostly organic. The paper presents the correlation parameters and information on their reliability. The chief advantage of the method is that it allows second virial coefficients to be evaluated reliably over a fairly wide temperature range even for substances for which limited experimental data are available. The proposed relation is also suitale for reliable determination of B derivatives required for calculations of thermodynamic state functions.