# 5. Physics Model

Molecular Dynamics simulation (MD) is a powerful method to study atomic and molecular processes. In plasma physics, it has vast applications starting from fusion plasma to dusty plasma. It solves the equation of motion using Newton equations of motion (or Langevin dynamics which includes energy dissipation through an additional friction term):

\[\frac{\partial^{2}}{\partial {t}^2}\vec{r}_i = \frac{1}{m_i}\vec{f}_i
\vec{f}_i=-\frac{\partial}{\partial r} V(\vec{r}_1(t), \vec{r}_i(t),~...,~\vec{r}_N(t))\]

where \(\vec{r}_i(t)\) is the position of atom \(i\) at time \(t\) with mass \(m_i\), and \(V\) is the interaction potential between all \(N\) involved species.