Temperature and density dependence of self-diffusion in supercooled liquid CS2

摘要: The self-diffusion coefficient (D) of liquid CS2 has been determined by computer simulation for seven densities (ρ) and eight temperatures, spanning more than two decades D in the supercooled near-melting normal liquid, bracketing P=1 atm isobar. Super-Arrhenius behavior −log D vs 1/T, an increase slope with decreasing T, is found at 1 atm, but Arrhenius T dependence holds along all different isochores, even highest density lowest T. super-Arrhenius a consequence variation ρ(T) constant pressure. Physically meaningful activation energies, representative heights barriers to diffusion, depend upon ρ only, are smaller isobaric slope, may be obtained correcting it or from plot density. Barriers diffusion indeed higher lower only due importance as “control variable” examined. Temperature and...