Molecular Simulations with in-deMon2k QM/MM, a Tutorial-Review

Area of Science:

• Computational Chemistry
• Theoretical Chemistry
• Molecular Dynamics

Background:

• Density Functional Theory (DFT) is a powerful computational method for electronic structure calculations.
• Quantum Mechanics/Molecular Mechanics (QM/MM) integrates quantum and classical mechanics for complex systems.
• deMon2k is a specialized program facilitating DFT simulations.

Purpose of the Study:

• To provide a tutorial-review of deMon2k's capabilities for molecular simulations.
• To demonstrate its application in studying ground and excited electronic states.
• To showcase QM/MM methodologies for various chemical and physical phenomena.

Main Methods:

• Utilizes Density Functional Theory (DFT) within the Auxiliary DFT framework.
• Implements additive Quantum Mechanics/Molecular Mechanics (QM/MM) with polarizable and non-polarizable force fields.
• Includes methods for geometry optimization, Born-Oppenheimer and Ehrenfest molecular dynamics, and attosecond electron dynamics.

Main Results:

• Demonstrates deMon2k's versatility through six diverse applicative examples.
• Covers reactivity studies, free-energy profiles (umbrella sampling, metadynamics), spectral simulations, and electron transfer reactions.
• Shows capabilities for computing electric and magnetic properties with QM/MM.

Conclusions:

• deMon2k offers a comprehensive suite of tools for advanced molecular simulations.
• The program effectively handles complex systems and diverse phenomena from reactivity to dynamics.
• Its flexibility and implemented methods make it valuable for computational chemistry research.