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.