Fast quasi-centroid molecular dynamics

Area of Science:

• Computational chemistry
• Molecular dynamics
• Quantum mechanics

Background:

• Quasi-centroid molecular dynamics (QCMD) is a method for simulating quantum mechanical effects in molecular systems.
• Accurate QCMD simulations can be computationally expensive.

Purpose of the Study:

• To develop a computationally efficient implementation of the QCMD method.
• To approximate the quasi-centroid potential of mean force for faster simulations.

Main Methods:

• Approximated the quasi-centroid potential of mean force as a separable correction to the classical interaction potential.
• Calculated quasi-centroid radial and angular distribution functions using path integral molecular dynamics.
• Employed iterative Boltzmann inversion to derive an effective classical potential.

Main Results:

• Achieved excellent agreement with QCMD reference calculations for water and ammonia vibrational spectra.
• Obtained good agreement with quantum mechanical vibrational spectra for methane.
• Demonstrated the efficiency of the fast QCMD implementation.

Conclusions:

• The developed fast QCMD implementation provides an accurate and efficient approach for molecular simulations.
• This method effectively captures quantum mechanical effects in vibrational spectra calculations.
• The approach is suitable for studying gas-phase molecules.