Hauptseminar Moderne Simulationsmethoden WS 2009/Fortgeschrittene Molekulardynamik I
- Fortgeschrittene Molekulardynamik I: Wie man die freie Energie berechnet
- Andreas Irmler
- Shervin Rafatnia
Vortrag (500 KB)
Ausarbeitung (267 KB)
- Chapter 7
Kurz zum Inhalt
The aim of this seminar would be to give a short introduction to free energy and to discuss some methods of calculating this energy in a MC or MD simulation.
In thermodynamics, the term free energy refers to the amount of work that can be extracted from a system. It is a subtraction of the entropy of a system multiplied by a reference temperature (giving the "unusable energy") from the total energy, yielding a thermodynamic state function which represents the "useful energy".
Free energy governs thermodynamic processes; all systems minimize their free energy to reach equilibrium. Therefore, calculating the free energy of a system is of great importance. But doing so in a simulation is not always easy. There are different methods to calculate the free energy of a system in MD or MC simulations. One can mention the thermodynamic integration method, the particle insertion method, overlapping distribution method, umbrella sampling and a few others.
- Thermodynamische Integration
- Widom's Teilcheneinsetzungsmethode