BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Proper Statistical Sampling in Isothermal-Isobaric Discrete-Time M
 olecular Dynamics - Prof. Oded Farago (Ben Gurion and Cambridge Chemistry)
DTSTART:20190122T130000Z
DTEND:20190122T140000Z
UID:TALK116263@talks.cam.ac.uk
CONTACT:Professor Mike Cates
DESCRIPTION:Abstract: Molecular Dynamics simulations always involve a disc
 retization of time\, but the discrete-time behavior is increasingly differ
 ent from that of the continuous-time physical equations as the time step i
 s increased. This fact creates a dilemma for any simulation of a dynamical
  system: Use a small time step\, resulting in dynamics that resemble conti
 nuous-time behavior at the expense of efficiency\; or use a large time ste
 p that makes the simulation finish sooner at the expense of meaningful evo
 lution. It is\, therefore\, essential to understand the features of differ
 ent algorithms\, such that optimal properties can be chosen for a given se
 t of problems and objectives.\n\nOur aim is to investigate and improve Mol
 ecular Dynamics simulation techniques for systems in thermal equilibrium. 
 I will present a simple derivation of a stochastic Stormer-Verlet algorith
 m for the evolution of Langevin equations. The method\, which is as simple
  as conventional Verlet schemes\, has been numerically tested on both low-
 dimensional nonlinear systems as well as more complex molecular ensembles 
 with many degrees of freedom. In light of the fundamental artifacts introd
 uced by discrete time to dynamical simulations\, I will provide a simple i
 ntuitive picture of the unique benefits of our algorithm that\, unlike oth
 er algorithms\, preserves proper configurational sampling (diffusion and B
 oltzmann distribution) in discrete time. I will also introduce a companion
  algorithm for controlling pressure in molecular ensembles\, i.e.\, a baro
 stat for NPT simulations. 
LOCATION:MR11\, CMS
END:VEVENT
END:VCALENDAR