Transport Properties of Monatomic Insulating Liquids and Liquid Alkali Metals from a Cage Model

A cage model is used to calculate the shear viscosity m s and the thermal conductivity s for insulating monatomic liquids and for liquid alkali metals. Three empirical laws: (i) $ \eta_s \, \propto \, (1/\sqrt T ) $ for liquid alkalis; (ii) s / m s ～ constant for Rb and Cs respectively; (iii) $ ({\gamma / {\eta _s }})\sim \sqrt {{{k_B T_m } / M}} $ for liquid alkalis at the melting temperature T m , where n is the surface tension and M the ionic mass, are naturally explained.