Metallic systems, like nanoparticles and metal surfaces, pose a significant challenge for the modern force field used in classical and hybrid quantum/classical mechanics simulations. The root of this problem is a complexity of electrostatic interaction in metallic systems, which is poorly described by point charges electrostatics used in conventional force fields. In recent years, several polarizable force fields based on fluctuating charges or fluctuating charges/dipoles electrostatics have been introduced and successfully applied to study silver and gold surfaces. Unfortunately, the computational cost of these force fields is significantly limit their applicability to extended metallic systems, like nanoparticles.<br/>In recent years, we have developed a hybrid QM/CMM approach [1,2] for studying properties of physisorbed on metallic surfaces and successfully applied our method to investigated metallic surface induced changes in linear and non-linear optical properties of various molecules. In this talk, I present our recent work on transforming interacting fluctuating charges/dipoles atomistic force field used in QM/CMM approach into coarse grain force field for the description of realistic nanostructures. The details of the new coarse graining scheme, which uses various surfaces of a metal unit cell for coarse grain representation, will be presented along with efficient solver for determination of fluctuating charges and dipoles. Apart from describing our new force field, I will also discuss the parameterization of our force field for gold, silver, and mixed gold/silver systems and present pilot application to rigid body Monte-Carlo simulations of gold and silver nanostructures ordering under the influence of external electric field.<br/><br/>

Polarizable coarse grain force field for metallic systems: A discrete interacting multipole model

2019 Spring National Meeting

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