Classical trajectories on simple model potentials for N2–Kr: Comparison with relaxation and other data

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Abstract
We compare the ability of six N2–Kr potential energy surfaces to predict experimental interaction second virial coefficients, diffusion coefficients, mixture viscosity,thermal conductivity, and nuclear magnetic resonance(NMR) rotational relaxation cross sections. These include a previously published empirical surface derived from fits to molecular beam experiments and various model potentials of the Tang and Toennies (TT) type. The TT type potentials differ in the set of dispersion coefficients employed. Two sets are obtained from published ab initio calculations, another from combining rules and one from empirical considerations. The repulsive parameters have been obtained from published results of a charge overlap combining rule. A variation of the TT model suggested by Aziz is also used to further investigate the effect of the repulsive wall anisotropy on the rotational relaxation cross sections. Forty‐five effective cross sections that determine the bulk transport and relaxation phenomena have been calculated by classical trajectories for temperatures ranging from 100 to 800 K. The sensitivity of the NMR‐derived cross sections to the various characteristics of the anisotropy of the potential (such as the anisotropy in the well depth, in the high repulsive wall, in the low repulsive wall, and at V=0) are examined. The empirical anisotropic LJ(12,6) surface of Rotzoll provides the best agreement with the diffusion,viscosity,thermal conductivity, and NMR relaxation experimental results.