VFFDT: A New Software for Preparing AMBER Force Field Parameters for Metal-Containing Molecular Systems

Area of Science:

• Computational Chemistry
• Molecular Modeling
• Biophysics

Background:

• Force fields are essential for molecular dynamics (MD) simulations but often lack complete parameters, particularly for metal-containing systems.
• Previous work established a method for deriving zinc-related AMBER force field parameters using the Seminario method and Hessian matrices.

Purpose of the Study:

• To develop a user-friendly toolkit (VFFDT) for simplifying the derivation of molecular dynamics force field parameters.
• To extend support for various quantum mechanics (QM) packages and introduce an automated parameterization protocol.

Main Methods:

• Implementation of a Visual Force Field Derivation Toolkit (VFFDT) with a 3D viewer interface.
• Support for Hessian matrix output from multiple QM packages (Gaussian, ORCA, QChem, GAMESS-US, MOPAC) via a universal VFFDT XYZ file format.
• Introduction of a semiempirical quantum mechanics (SQM) based protocol for instant force field parameterization.

Main Results:

• The VFFDT enables users to derive force field parameters by interacting with bonds or angles in a 3D viewer.
• Automated generation of parameters for metals like zinc, copper, and iron, exportable in AMBER Frcmod format.
• The toolkit supports reading and writing AMBER file formats (Prepc, Frcmod, Mol2) and offers parameter customization, viewing, and manipulation functionalities.

Conclusions:

• The VFFDT significantly simplifies the force field parameter derivation protocol, making it more accessible.
• The toolkit complements existing AmberTools utilities (ANTECHAMBER, MCPB, MCPB.py) by providing enhanced functionality for metal systems.
• This development addresses the long-standing challenge of incomplete force field parameters in computational simulations.