QuickFF: A program for a quick and easy derivation of force fields for metal-organic frameworks from ab initio input

Area of Science:

• Computational Chemistry
• Materials Science

Background:

• Accurate force fields are crucial for molecular simulations.
• Generating force fields, especially for complex systems like metal-organic frameworks (MOFs), often requires significant manual effort and expertise.
• Existing methods can be labor-intensive and prone to fitting deficiencies.

Purpose of the Study:

• To introduce QuickFF, a software package designed for rapid and accurate force field generation.
• To automate the derivation of force field parameters from ab initio data.
• To provide a user-friendly tool for creating force fields for diverse molecular systems, with a focus on MOFs.

Main Methods:

• QuickFF utilizes a three-step method to derive covalent interaction parameters from ab initio data.
• The methodology minimizes parameter correlations and refines parameters to reproduce the ab initio Hessian matrix.
• Users provide an equilibrium structure and Hessian matrix for building units.

Main Results:

• The software successfully generated accurate force fields for a set of 1000 organic molecules, demonstrating ease of use.
• QuickFF was applied to generate force fields for MIL-53(Al) and MOF-5, requiring minimal manual intervention compared to previous methods.
• The implemented method ensures robustness by using a simplified mathematical expression for covalent energy.

Conclusions:

• QuickFF offers an efficient and automated solution for generating accurate force fields.
• The software is accessible to users with basic knowledge of ab initio calculations.
• QuickFF significantly reduces the effort required for force field development, particularly for MOFs.