A simplistic model of atomic dynamics in liquid, based on the concept of dynamic fluctuations in local atomic connectivity, is proposed to elucidate the temperature variation of the viscosity of a material in its liquid phase. Within the simplifications and hypothesis made to define the model, it is possible to explain the crossover from a simple liquid to a cooperative liquid and covariance of viscosity near the glass transition temperature. The model is a mechanical analog of the Drude model for the electric transport in metal.

• Received 20 June 2018

DOI:https://doi.org/10.1103/PhysRevE.98.063005