Estimating the viscosity coefficient of liquid metals from Vibration-Transit theory

We describe and test a simple method for calculating the viscosity coefficient $\eta$ for liquid metals over a range of densities and temperatures. The method uses a model of atomic motion in a liquid based on the Vibration-Transit (V-T) theory of liquid dynamics to calculate the self-diffusion coefficient $D$, and then uses $D$ and the Stokes-Einstein relation to compute $\eta$. We consider the accuracy of both the V-T model for $D$ and the Stokes-Einstein relation; we then compute $\eta$ for 21 liquid metals at melt at 1 bar, finding that our results agree with experiment to $18\%$ accuracy. This is somewhat more accurate than other empirical methods and not much less accurate than first priciples molecular dynamics calculations, while being substantially less computationally intensive than the latter.