Review
Molecular dynamics is a numerical integration of the classical equations of motion
Total energy is strictly conserved, so MD samples the NVE ensemble
Dynamical behaviors can be measured by taking appropriate time averages over the simulation
- Spontaneous fluctuations provide non-equilibrium condition for measurement of transport in equilibrium MD
- Non-equilibrium MD can be used to get less noisy results, but requires mechanism to remove energy via heat transfer
Two equivalent formalisms for EMD measurements
- Einstein equation
- Green-Kubo relation
time correlation functions