US – Page 431 – TechConnect Briefs

Multiscale Simulation of the Thermal Desorption of Large Molecules from Solid Surfaces

Fichthorn K., Miron R.A., Kulkarni A., Pennsylvania State University, US

We use molecular-dynamics simulations and importance sampling to obtain transition-state theory rate constants for thermal desorption of an n-alkane series from Pt(111). These simulations indicate that the binding of a large molecule to a solid [...]

Growth of Copper on Ag(100) at Experimental Deposition Rates Using TAD

Sprague J., Montalenti F., Voter A.F., Naval Research Laboratory, US

The initial stages of growth of (001) Cu films on (001) Ag substrates have been investigated using the temperature accelerated dynamics (TAD) method. The acceleration provided by this method made it possible to simulate the [...]

Accelerated Dynamics Simulations of Nanotubes

Uberuaga B., Stuart S.J., Voter A.F., Los Alamos National Laboratory, US

We report on the application of accelerated dynamics techniques to the study of carbon nanotubes. We have used the parallel replica method and temperature accelerated dynamics simulations are currently in progress. In the parallel replica [...]

Multiscale Detection of Temporal Features in Molecular Dynamics Simulations:Applications to Acceleration Methods

Richie D., Kim J., Wilkins J.W., High Performance Technologies, Inc., US

Extending the time scales accessible through direct molecular dynamics simulations is an area of active research. New acceleration techniques promise to achieve experimentally relevant time scales. A common ingredient in many of these acceleration schemes [...]

Simulations of Dopant Clustering in Silicon: Dimer calculations using DFT forces

Henkelman G., Uberuaga B., Dunham S., University of Washington, US

We have carried out computer simulations to study the formation and break-up of boron clusters in crystalline silicon. Density functional theory was used to evaluate the interatomic interactions and dimer method used to nd the [...]

Accelerating Molecular Dynamics Simulations

Germann T.C., Voter A.F., Los Alamos National Laboratory, US

In contrast with the converging length scales of atomistic simulations and experimental nanoscience, large time scale discrepancies still remain, due to the time-scale limitations of molecular dynamics. We briefly review two recently developed methods, derived [...]

Dimer-method Long Time Scale Simulations of Surface Growth

Henkelman G., University of Washington, US

We have carried out long time scale simulations where the dimer method [G. Henkelman and H. Joonsson, J. Chem. Phys. 111, 7010 (1999)] is used to find the mechanism and estimate the rate of transitions [...]

Temperature Accelerated Dynamics: Introduction and Application to Crystal Growth

Montalenti F., Los Alamos National Laboratory, US

Temperature accelerated dynamics (TAD) simulations allow one to reach long time scales without needing any a priori information on the system dynamics. As a consequence, TAD is a powerful method for simulating complex phenomena where [...]

Introduction to the Time Scale Problem

Voter A.F., Los Alamos National Laboratory, US

As motivation for the symposium on extended-scale atomistic methods, I briefly discuss the time scale problem that plagues molecular dynamics simulations, some promising recent developments for circumventing the problem, and some remaining challenges.

Water Conduction Through Carbon Nanotubes

Hummer G., Rassaiah J.C., Noworyta J.P., National Institutes of Health, US

In molecular dynamics simulations we found that water can form hydrogen-bonded water chains in the interior of carbon nanotubes. Water penetration is sensitive to details of thermodynamic conditions and interaction potentials, resulting in sharp, first-order [...]