Berendsen Barostat

Many of the approaches used for controlling the pressure are similar to those that are used for controlling the temperature. One approach is to maintain constant pressure by coupling the system to a constant pressure reservoir as is done in the Berendsen barostat (Berendsen et al. 1984), which is analogous to the way temperature is controlled in the Berendsen thermostat The pressure change in the system is determined by 

One other input that may be included in the use of the Berendsen barostat is to define which dimensions are coupled during the pressure relaxation. For example, you could define that the pressure is relaxed in a way that the changes in aU three dimensions are coupled and therefore aU of the dimensions change at the same rate. On the other hand, the pressure relaxation can be handled in an anisotropic manner, such that none of the dimensions are coupled and each dimension wiU have its own scaling factor that results from the individual pressure components. 

---

The MD simulations can be perfomed in maity different ensembles, such as grand canonical (pVT), microcanonical (NVE), canonical (NVT) and isothermal-isobaric (NPT). The constant temperature and pressure can be controlled by adding an appropriate thermostat (e g., Berendsen, Nose, Nose-Hoover, and Nose-Poincare) and barostat (e.g., Andersen, Hoover, and Berendsen), respectively. Applying MD into polymer composites allows us to investigate into the effects of fillers on polymer stracture and dynamics in the vicinity of polymer-filler interfaee and also to probe the effects of polymer-filler interactions on the materials properties. 

---