| Abstrakt: |
For the purpose of obtaining the density dependence of the effective mass in a classical simple liquid, the parameters appearing in the most general equations of motion in the itinerant oscillator model are determined for various reduced densities ρ* = ρ'σ3(ɛ/kT)1/4 (ɛ>0, σ>0 and ρ' is a number density) for the model liquid with the twelfth inverse power potential ϕ(r)=ɛ(σ/r)12. In particular the density dependence of the effective mass for this model liquid both for higher and lower ρ* region is exhibited in detail. The diverging point ρe* of the effective mass, which corresponds to the falling point of the self-diffusion coefficient, is shown to lie between ρe* =1.266 and 1.562. Two trial expressions for the effective mass are proposed in terms of the immobility and the correlation distance of a single diffusing atom: One indicates that the potential barrier over which the diffusing atom must jump is not very high, and the other reveals that the correlation distance is unexpectedly short. |
