Atomic Polarizabilities for Interactive Dipole Induction Models.

Area of Science:

• Computational Chemistry
• Molecular Modeling
• Quantum Chemistry

Background:

• Thole-style mutual induction models are crucial for polarizable force fields (FFs) due to their simplicity and transferability.
• Current atomic polarizability parameters are typically fitted to ab initio or experimental data.
• Existing methods may not fully capture polarization effects, especially for atoms with lone pair electrons.

Purpose of the Study:

• To improve Thole-style atomic polarizability parameters for enhanced accuracy in molecular simulations.
• To explore the efficacy of high-level quantum mechanics and electrostatic potential (ESP) methods for parameter derivation.
• To develop a transferable set of parameters applicable to a wide range of organic molecules.

Main Methods:

• Derived atomic polarizability parameters using high-level quantum mechanics molecular polarizabilities.
• Employed electrostatic potential (ESP) responses on 3D grids to derive parameters.
• Validated parameters against 7200+ molecules and 422 experimental molecular polarizabilities.

Main Results:

• Both quantum mechanics and ESP approaches effectively derived atomic polarizability parameters.
• ESP approaches demonstrated capability in capturing polarization for atoms with lone pair electrons.
• The new parameter set shows significant improvement over the current AMOEBA set and exhibits high transferability.

Conclusions:

• The developed atomic polarizability parameters offer enhanced accuracy and transferability for Thole-style models.
• These parameters are defined by the local chemical environment using SMARTS patterns, enabling broader applicability.
• The improved parameters can be directly integrated into popular polarizable potential energy functions like AMOEBA and AMOEBA+.