Connecting time and space scales
Molecular modeling

Molecular modeling methods represent matter at the spatio-temporal scale of the atom, whose units are typically the bohr (≍ 0.05 nm) and the femtosecond (10^–15 s).

An atomistic simulation based on force fields can apprehend, in the current state of computing capabilities, the temporal evolution of a volume element containing of the order of 10⁶ atoms over a duration of the order of nanoseconds (≍ 10⁶ time steps).

In ab initio calculation, tracking the order of 10³ atoms over a few picoseconds (10³ time steps) already represents a tour de force.

While statistical physics assures us that macroscopic phenomena are reducible to microscopic phenomena, the question of the statistical representativeness of the sampling he carries out constantly arises for the practitioner of molecular simulations and modeling: do such simulations...