Determining polarizable force fields with electrostatic potentials from quantum mechanical linear response theory.

Area of Science:

• Computational Chemistry
• Quantum Mechanics
• Molecular Modeling

Background:

• Atomic polarizabilities are crucial for accurate molecular simulations.
• Conventional methods often require extensive quantum mechanical (QM) calculations.
• Existing methods may not optimally capture electrostatic interactions.

Purpose of the Study:

• To develop a new, efficient QM-based method for calculating atomic polarizabilities.
• To improve the accuracy of electrostatic interactions in molecular modeling.
• To provide a method for both transferable and molecule-specific atomic polarizabilities.

Main Methods:

• Fitting atomic polarizabilities to electrostatic potentials (ESPs) from QM calculations.
• Utilizing linear response theory and an induced dipole model.
• Integrating QM calculations with uniform external electric fields in all orientations.

Main Results:

• The new method achieves comparable accuracy to existing approaches for molecular polarizabilities.
• The fitting process is independent of the orientation and magnitude of applied electric fields.
• Requires only one QM calculation, significantly reducing computational cost compared to conventional methods.

Conclusions:

• The developed method provides an accurate and efficient way to compute atomic polarizabilities.
• This approach enhances the reproduction of electrostatic interactions in molecular models.
• Applicable for creating both transferable and molecule-specific atomic polarizabilities for force fields.