Polarizable charges in a generalized Born reaction potential

Area of Science:

• Computational chemistry
• Molecular modeling
• Physical chemistry

Background:

• The Generalized Born (GB) model is a rapid implicit solvent method approximating the Poisson equation for charged solutes.
• GB models are frequently employed in molecular dynamics (MD) simulations to incorporate solvation effects.
• Current GB models are primarily designed for fixed charges, limiting their application to systems with charge polarization.

Purpose of the Study:

• To extend the Generalized Born (GB) model for simulating polarizable charges.
• To develop a novel implicit solvation model that integrates solute polarization with solvation effects.
• To assess the performance and stability of the new model in molecular dynamics simulations.

Main Methods:

• Coupling the Generalized Born (GB) model with the Bond Capacity (BC) model to create the BC-GB model.
• Implementing a non-variational polarization approach using a Lagrange formulation for efficient energy gradient calculation.
• Testing the BC-GB model's stability and energy conservation in microcanonical ensemble MD simulations.

Main Results:

• The BC-GB model successfully incorporates implicit solvation effects for polarizable charges.
• MD simulations demonstrated good energy conservation and minimal fluctuations, indicating algorithmic stability.
• The computational overhead of including implicit solvation was a modest 15% increase over vacuum calculations.

Conclusions:

• The BC-GB model offers an efficient method for simulating polarizable solutes in implicit solvents.
• Its computational efficiency and ability to handle polarization make it suitable for extensive conformational sampling.
• This model advances the simulation of complex molecular systems where both polarization and solvation are critical.