where η αβ is the shear viscosity for components α, β, V and T are the system volume and temperature, t is the time, P αβ is the off diagonal component of the pressure tensor and ⟨P αβ (0)P αβ (t)⟩ is the pressure autocorrelation function (PACF). There are three off diagonal components of the pressure tensor; P xy , P xz , P yz and three corresponding viscosity components; η xy , η xz , η yz . The shear viscosity, η, was taken as the average of the 3 η αβ components.