Local bias potential in hyper molecular dynamics method

The hyper molecular dynamics method (Hyper-MD) with a local bias potential can be used in massive simulations on infrequent events with a very small computation overhead. In this paper, we demonstrate the validity of the local bias potential in simulation of various systems, and study how the results depend on the locality of the bias potential. For an adatom diffusion on surface or interstitial diffusion in bulk, we find that a local bias potential only related to the neighbors of the interesting atoms is good enough. Our studies also show that the Hyper-MD with a local bias potential can be used to study the surface diffusion with exchange mechanism.