3. Discuss the basic idea of MD simulation that distinguishes it from quantum mechanics calculation. Using this concept, derive the equation of motion to produce an algorithm integrating a numerical solution in order to predict the trajectory of the atoms or molecules in a system. Explain the advantages of this algorithm. A real system usually contains a massive number of atoms which is impossible to translate into simulation. On the other hand, using a small system creates an interference in the simulation. Discuss these limitations with an example for each, supported with mathematical calculation. Propose and explain a technique to solve this problem. In addition, classical MD technique is time consuming, run at nanoseconds or microseconds requiring millions of energy gradient calculations. Rather than using a high-performance computer to overcome this downside, choose with justification TWO (2) methods that can help to reduce computing time for simulations. [40 marks)