The transport coefficients of gases (self-diffusion, viscosity, and heat conductivity) can be determined via formulas containing the collision integrals, which depend on the chosen potential function. A new method for calculating the collision integrals for the more general O'Connell-Prausnitz potential function is presented. The two innermost integrals of the collision integral, i.e., the angle
... [Show full abstract] of deflection and the reduced cross section, are determined by integration algorithms. These algorithms account for all numerical errors, the truncation error as well as the rounding errors. Furthermore, they take the singularity of the integrand of the angle of deflection and the oscillating point of the integrand of the reduced cross section into account. Using the verified values of the reduced cross section, we determine the collision integrals by approximate integration. A comparison of the verified values of the angle of deflection and of the reduced cross section with their corresponding approximate values taken from another publication is presented. Furthermore, numerical results for the transport coefficients of R152a calculated for the Kihara and the O'Connell-Prausnitz potential function are compared with experimental results.