Introduction

Adiabatic-bias Molecular Dynamics (ABMD) is a simple and reasonably inexpensive MD based technique in which a variable biasing potential is used to direct the simulated system from an initial to a final configurational state separated by a free energy activation barrier. 

ABMD is a simulation method in which a time-dependent biasing potential is used to drive a system from an initial to a final state along a predefined reaction coordinate. The equilibrium position of the harmonic biasing potential begins at the initial position on this coordinate. Whenever the system moves to a position further along the coordinate, the equilibrium position of the harmonic potential is moved to this new position, effectively pushing the system towards the final state. If the force constant of the potential is small enough, the harmonic potential will be numerically zero as the simulation passes the equilibrium position, and therefore no heating will occur.

Computational Tools

Adiabatic-bias Molecular Dynamics (ABMD) can be performed using the following software tools:

Example Cases

Adiabatic-bias Molecular Dynamics (ABMD) was used in the following examples: