Free energy computation by controlled Langevin dynamics
نویسندگان
چکیده
We propose a nonequilibrium sampling method for computing free energy profiles along a given reaction coordinate. The method consists of two parts: a controlled Langevin sampler that generates nonequilibrium bridge paths conditioned by the reaction coordinate, and Jarzynski’s formula for reweighting the paths. Our derivation of the equations of motion of the sampler is based on stochastic perturbation of a controlled dissipative Hamiltonian system, for which we prove Jarzynski’s identity as a special case of the Feynman-Kac formula. We illustrate our method by means of a suitable numerical example and briefly discuss issues of optimally choosing the control protocol for the reaction coordinate.
منابع مشابه
Energy study at different solvents for potassium Channel Protein by Monte Carlo, Molecular and Langevin Dynamics Simulations
Potassium Channels allow potassium flux and are essential for the generation of electric current acrossexcitable membranes. Potassium Channels are also the targets of various intracellular controlmechanisms; such that the suboptimal regulation of channel function might be related to pathologicalconditions. Realistic studies of ion current in biologic channels present a major challenge for compu...
متن کاملGyration Radius and Energy Study at Different Temperatures for Acetylcholine Receptor Protein in Gas Phase by Monte Carlo, Molecular and Langevin Dynamics Simulations
The determination of gyration radius is a strong research for configuration of a Macromolecule. Italso reflects molecular compactness shape. In this work, to characterize the behavior of theprotein, we observe quantities such as the radius of gyration and the average energy. We studiedthe changes of these factors as a function of temperature for Acetylcholine receptor protein in gasphase with n...
متن کاملLangevin dynamics with constraints and computation of free energy differences
In this paper, we consider Langevin processes with mechanical constraints. The latter are a fundamental tool in molecular dynamics simulation for sampling purposes and for the computation of free energy differences. The results of this paper can be divided into three parts. (i) We propose a simple discretization of the constrained Langevin process based on a standard splitting strategy. We show...
متن کاملInvestigation of Monte Carlo, Molecular Dynamic and Langevin dynamic simulation methods for Albumin- Methanol system and Albumin-Water system
Serum Albumin is the most aboundant protein in blood plasma. Its two major roles aremaintaining osmotic pressure and depositing and transporting compounds. In this paper,Albumin-methanol solution simulation is carried out by three techniques including MonteCarlo (MC), Molecular Dynamic (MD) and Langevin Dynamic (LD) simulations. Byinvestigating energy changes by time and temperature (between 27...
متن کاملError Analysis of Modified Langevin Dynamics
We consider Langevin dynamics associated with a modified kinetic energy vanishing for small momenta. This allows us to freeze slow particles, and hence avoid the re-computation of inter-particle forces, which leads to computational gains. On the other hand, the statistical error may increase since there are a priori more correlations in time. The aim of this work is first to prove the ergodicit...
متن کامل