Prediction of diffusion coefficient for the Rb and Cs liquid alkali metals near melting point

A great deal of physical properties of liquid alkali metals including the dynamic propertieshas been measured. The relative simplicity of the electronic structure of these metals conferson them the status of an ideal benchmark for models and theories. For instance, it has oftenbeen proposed that alkali metals could present scalable properties. Liquid alkali metalsstructure factors resemble closely to hard-sphere (HS) reference systems, and calculations toevaluate static and dynamic properties have been found to be quite reasonable in many cases.It must be mentioned that short-range forces primarily determine the structure of a liquid andthe relatively long-range attractive part of the potential provides a uniform attractivebackground. The square-well (SW) fluid is the simplest one possessing the basiccharacteristics of a real fluid. Recently application of SW potential to liquids is being workedto evaluate various properties [1,2]. In this work, we are interested in the calculation ofdiffusion coefficients for several liquid alkali metals such as rubidium (Rb) and cesium (Cs)using the SW potential by the mean spherical model (MSM) approximation [3]. Also, wecompare the results obtained with experimental data and those obtained from the HS model.