Wavefunction-Based Electrostatic-Embedding QM/MM Using CFOUR through MiMiC.

Area of Science:

• Computational Chemistry
• Multiscale Modeling
• Quantum Mechanics

Background:

• Quantum mechanical (QM) calculations are computationally intensive.
• Multiscale modeling combines different levels of theory for efficiency.
• Integrating advanced QM methods into multiscale frameworks is crucial for complex systems.

Purpose of the Study:

• To develop and validate an interface between CFOUR and MiMiC.
• To enable efficient QM/MM simulations using wavefunction-based methods.
• To reduce the computational cost of ab initio molecular dynamics (AIMD) and QM/MM-MD simulations.

Main Methods:

• Analytic evaluation of one-electron integrals for electrostatic embedding.
• Multipole expansion of QM electron density for long-range interactions.
• Integration with the MiMiC framework for QM/MM operations.

Main Results:

• The CFOUR-MiMiC interface is robust and ensures fast self-consistent field convergence.
• Energy conservation during molecular dynamics integration is optimal.
• Compatibility with QM/QM multiple time-step algorithms was verified.

Conclusions:

• The developed interface facilitates accurate and efficient multiscale simulations.
• It supports various wavefunction approaches, including post-Hartree-Fock methods.
• This advancement reduces the computational burden of ab initio molecular dynamics simulations.