Fine-tuning of atomic point charges: Classical simulations of pyridine in different environments

A correct description of electrostatic contributions in force fields for classical simulations is mandatory for an accurate modeling of molecular interactions in pure liquids or solutions. Here, we propose a new protocol for point charge fitting, aimed to take into the proper account different polarization effects due to the environment employing virtual sites and tuning the point charge within the polarizable continuum model framework. The protocol has been validated by means of molecular dynamics simulations on pure pyridine liquid and on pyridine aqueous solution, reproducing a series of experimental observables and providing the information for their correct interpretation at atomic level.