Polarizable Embedding without Artificial Boundary Polarization

We present a fully self-consistent polarizable embedding(PE) modelthat does not suffer from unphysical boundary polarization. This isachieved through the use of the minimum-image convention (MIC) inthe induced electrostatics. It is a simple yet effective approachthat includes a more physically accurate description of the polarizationthroughout the molecular system. Using PE with MIC (PE-MIC), we shednew light on the limitations of commonly employed cutoff models, suchas the droplet model, when used in PE calculations. Specifically,we investigate the effects of the unphysical polarization at the outerboundary by comparing induced dipoles and the associated electrostaticpotentials, as well as some optical properties of solute-solventand biomolecular systems. We show that the magnitude of the inaccuraciescaused by the unphysical polarization depends on multiple parameters:the nature of the quantum subsystem and of the environment, the cutoffmodel and distance, and the calculated property.