A New Split Charge Equilibration Model and REPEAT Electrostatic Potential Fitted Charges for Periodic Frameworks with...

Area of Science:

• Materials Science
• Computational Chemistry
• Solid-State Physics

Background:

• Periodic frameworks with net charges, such as zeolites, are crucial in various applications.
• Accurate partial atomic charges are essential for simulating guest-host interactions within these materials.

Purpose of the Study:

• To investigate and validate methods for generating partial atomic charges in charged periodic systems.
• To address limitations of existing methods for handling net framework charges.

Main Methods:

• Examined REPEAT electrostatic potential fitted charges using periodic electronic structure calculations with a neutralizing background charge.
• Reformulated the split charge equilibration (SQE) method into SQE_AB (atomic basis) to handle non-neutral systems.
• Validated SQE_AB against REPEAT charges and the original SQE model using metal-organic frameworks and zeolites.

Main Results:

• The SQE_AB method provides results equivalent to the original SQE model for neutral systems.
• SQE_AB successfully captures the chemical structure of charged frameworks.
• The new SQE_AB method demonstrates improved accuracy compared to the standard charge equilibration model for charged systems.

Conclusions:

• The reformulated SQE_AB method is a reliable approach for generating partial atomic charges in both neutral and charged periodic frameworks.
• This advancement facilitates more accurate simulations of guest-host interactions in important materials like zeolites.