Simulations were performed to study the evolution of the properties of K-Cs alloys with composition (table 15). Interatomic interactions were described using a second-order pseudopotential-perturbation formalism. The validity of this model was ascertained by comparison with available experimental results of total structure. Partial structures were investigated in detail in relation with interaction features. The large size of the simulated box provided an accurate description of the low- q behavior of the partial structure factors, yielding some thermodynamic properties like the isothermal compressibility. Individual and collective dynamic properties were considered through the self-diffusion and interdiffusion coefficients. An analysis of these properties indicated a cancellation between homo-coordination and hetero-coordination tendencies so that the system behaved nearly like an ideal mixture in the whole range of compositions despite the complex metallic interactions. It was emphasized that such a behavior could be understood in terms of a competition between size asymmetry and attraction non-additivity on one hand, and attraction asymmetry on the other.

Large-Scale Molecular Dynamics Study of Liquid K-Cs Alloys: Structural, Thermodynamic, and Diffusion Properties. Wax, J.F., Jakse, N.: Physical Review B, 2007, 75[2], 024204

Table 16

Diffusion parameters for helium in the La-Al-Ni system