## Control of simulation The rest (after [[Initialization of simulation]]) depends on the system we want to model. Detailed temperature control (i.e., [[Thermostats and constant temperature MD|thermostats]]) will be discussed later, for cases that we want to model [[Ensemble#Canonical ensemble|canonical ensemble]]. But an initiative idea would be (temperature) rescaling, i.e., replace the coefficient 1 in [[Verlet algorithm#^1152db|velocity Verlet]]: $v\left( t+\frac{1}{2}\delta t \right) = v(t)+\frac{1}{2}a(t)\delta t$ replace with $\sqrt{\frac{T_0}{T(t)}}$, one may have $v\left( t+\frac{1}{2}\delta t \right) = \sqrt{\frac{T_0}{T(t)}} v(t) +\frac{1}{2}a(t)\delta t$ This is reasonable because $T$ is related to kinetic energy and velocity, $K=\frac{3}{2}NkT$. >[!notice] >Always remember, doing the velocity rescaling may cause some [[Thermostats and constant temperature MD#^edca50|problems]]!