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NVU dynamics. I. Geodesic motion on the constant-potential-energy hypersurface
Trond S Ingebrigtsen1, Søren Toxvaerd, Ole J Heilmann
1DNRF Centre Glass and Time, IMFUFA, Department of Sciences, Roskilde University, Postbox 260, DK-4000 Roskilde, Denmark.
The Journal of Chemical Physics
|September 22, 2011
Summary
A new algorithm simulates particle motion on constant potential energy surfaces. This modified algorithm ensures stability and conserves energy, matching standard methods for accurate simulations of liquids.
Area of Science:
- Computational physics
- Molecular dynamics simulations
Background:
- Simulating particle dynamics requires accurate algorithms.
- Constant potential energy simulations are crucial for understanding liquid properties.
Purpose of the Study:
- To develop a stable algorithm for simulating geodesics on constant potential energy hypersurfaces.
- To address numerical errors and entropic drift in existing algorithms.
Main Methods:
- Discretizing geodesic stationarity conditions with Lagrangian multipliers.
- Implementing a modified algorithm for potential-energy and step-length conservation.
- Testing with single-precision simulations of Lennard-Jones liquid.
Main Results:
- The basic algorithm shows good stability with smoothed force cutoffs and precise initial conditions.
- A modified algorithm eliminates entropic drift and ensures absolute stability.
- The modified algorithm yields identical radial distribution functions to standard NVE algorithms.
Conclusions:
- The developed NVU algorithm provides a stable and accurate method for constant potential energy simulations.
- This advancement is crucial for reliable molecular dynamics studies of liquids.
- The algorithm's stability and accuracy are validated through analytical and simulation-based evidence.
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