Kan-Ju Lin

• Simulations are relatively simple, inexpensive, and everything can be measured in principle.
• Not to reproduce experimental results (exception: testing the accuracy of potentials)
• Help to understand experimental results or to propose new experiments
• Test of theoretical predictions or theories
• Investigating systems on a level of detail which is not possible in real experiments or analytical theories (local structure, mechanics .., etc.)
• Create new materials

Computer simulations often use an atomistic approach to find answers to interesting effect, technical problems, and theoretical predictions. At atomistic level simulation, particles interacting with each other is described by two methods:

ab initio calculation:

- positions of atoms -> electronic

- structure of the system -> potential

- computationally very expensive

Effective potential:

- Forms of potential is ad hoc.

- Parameters are obtained from fitting experimental data or restuls from ab initio calculations

- Cheap

The bottleneck for effective potentials (classical MD simulation) is about the time scale and accuracy of the potential, which have to be overcome so that the simulation can develop in their full capacity.