Excess entropy scaling of the transverse sound speed in simple fluids

A calculation of the transverse sound velocity as a function of excess entropy is presented for several simple fluids, including the Lennard-Jones, Yukawa, one-component plasma, inverse-power law (soft sphere), and hard-sphere models. A quasi-universal character of this dependence is established, extending Rosenfeld's excess-entropy scaling of transport coefficients to the transverse sound velocity. The results are discussed in terms of the soft- to hard-sphere crossover and the Frenkel crossover between gas-like and liquid-like dynamics.