Give some references about the temp property.
The coordinates of previous step will be tracked.
Energies (total, potential, kinetic) will be kept.
The previous coordinates will not be kept. The energy terms will be kept.
Add two parameters, sigma and epsilon, for LJ potential computing.
Add box size and square of cutoff radius.
Initial commit for solving equation of motion with leap frog algorithm. The verlet algorithm has not been implemented.