Approaching post-Hartree–Fock quality potential energy surfaces with simple pair-wise expressions: parameterising point-charge-based force fields for liquid water using the adaptive force matching method

Abstract

This article summarises the adaptive force matching (AFM) method recently developed by the Wang group. The AFM method is capable of parameterising force fields in the condensed phase by fitting electronic structure forces obtained through quantum mechanics/molecular mechanics (QM/MM) calculations. The AFM method utilises an iterative procedure to ensure good sampling and high-quality MM models for QM/MM calculations. By fitting forces directly in the condensed phase, simple pair-wise additive potentials parameterised following AFM can account for many-body effects implicitly. The AFM method provides a mechanism for judging the effectiveness of force field terms and the quality and transferability of the final force field. Realising the limitation of simple potentials, AFM emphasises fitting problem-specific force fields instead of a universal force field. This article provides a demonstration using the recently developed density functional theory/supplemental potential method to provide reference forces to parameterise a four-site point-charge model, BLYPSP-4F, for liquid water in the temperature range from 0 to 40°C. No experimental information was used for the development of BLYPSP-4F the model is found to satisfactorily reproduce experimental properties.

Keywords:

• force field development
• adaptive force matching
• molecular dynamics