The following equation: ε = σV2/3 = a – bT (1) holds for average one-particle binding energy ε of any molecule situated on surface of a liquid. Hereafter σ, V and T are its surface tension, molar volume and absolute temperature respectively. The quantity a means the value of ε when T goes to zero. In its turn the value of b is equal to a/Tc, were Tc is the critical temperature of the liquid, when T goes to Tc, then σ goes to zero. In the present work we consider, that a = 1/2(ε2 - 2ε1) (2) were ε2 and ε1 are respectively the energy values of molecular dimeric and monomeric forms of the given liquid. In this case we can write the following equation: σV2/3 = 1/2c×(ε2 - 2ε1)×(1-T/Tc), (3) where c is some coefficient of proportionality. Thus, one can see the clear-cut linear dependence between the quantities σV2/3 and 1/2 (ε2 - 2ε1)×(1- T/Tc). To verify this fact a series of organic compounds was calculated at DFT B3LYP level. The results are presented in Table 1 and in Figure 1, where σ, V and Tc were taken from [1]. It is seen that Eq. 3 (see above) describes the surface tension of organic liquids properly. Thus, basing on DFT calculations, we can define this important property for various liquid organic substances. Table 1. To the linear dependence between σV2/3 and a.figureFigure 1. The linear dependence between σV2/3 and a