phase). The resulting energy difference is now assumed to be dissipated into the bulk crystal via phononic excitations and is ultimately lost as heat. Although the method is quasi-static the resulting frictional forces can be predicted sufficiently well, if the amount of energy that is lost during sliding is estimated correctly. The relaxed energy surface is also corrugated, thus, the movement to the next minimum may result in small gains or losses in the energy leading to small negative or positive friction forces along this portion of the path. This is the second part of the “slip” phase. When the next minimum in the unrelaxed surface is encountered the cycle is repeated until the desired path length is reached. If the local minimum of the unrelaxed energy curve is not at the same energy as the relaxed curve, an appropriate portion of the released energy from the last slip is used to bring the system back to the unrelaxed sliding position. With this method we avoid the use of springs to model the elasticity of the system, which is instead included implicitly in the relaxations. The process is visualized in Fig. \[fig:2\].

![Illustration of the energy dissipation model along a 