Free energy surface as a function of two torsional angles for a dialanine dipeptide in water solution. The atomic configurations corresponding to the stable conformers are also represented. The free energy surface is reconstructed by a novel and powerful method for exploring the properties of complex many-body systems [Laio A. and Parrinello M. Proc Natl. Acad. Sci. USA, 99, 12562, (2002)].
A characteristic feature of this method is the presence of a history-dependent potential term that, in time, fills the minima in the free energy surface, allowing the efficient exploration and accurate determination of the free energy surface as a function of the collective coordinates.
Div-X-encoded AVI movie (1.16 Mb)
Data simulation by Alessandro Laio, CSCS