Water structures on Pb(100) and (111) surface studied with the Interface force field

Abstract

We performed classical molecular dynamics (CMD) simulations of water structures on Pb(100) and (111) surfaces. The main objective was to test the capability of Interface force field to reproduce water structures obtained from more computationally intensive ab initio molecular dynamics (AIMD) simulations. At the same length and time scales we found good agreement between water structures obtained with both approaches. However, much longer trajectories (ns vs. ps scale) that can be simulated with CMD led to the formation of different, more stable water structures, which were validated by supplementary ab initio calculations. CMD simulations performed for interface models with larger surface unit cells revealed significant surface cell size effects, implying that the small simulation cells permitted by AIMD could be insufficient to obtain properly equilibrated water structures. These results indicate the usefulness and advantage of CMD simulations that employ the Interface force field for the rapid sampling of more realistic time and length scales in simulations of metal-aqueous solution interfaces.