Efficient evaluation of accuracy of molecular quantum dynamics using dephasing representation.

Area of Science:

• Quantum chemistry
• Computational physics
• Molecular dynamics

Background:

• Accurate electronic structure calculations are vital for molecular properties.
• Ab initio methods provide high accuracy for static properties but are computationally expensive for quantum dynamics.
• Existing methods struggle with the computational cost of high-level quantum dynamics simulations.

Purpose of the Study:

• To develop an efficient semiclassical method for evaluating quantum dynamics accuracy.
• To enable comparison between lower and higher level quantum dynamics without performing full quantum dynamics calculations.
• To provide a computationally feasible tool for assessing the accuracy of quantum dynamics simulations.

Main Methods:

• A novel semiclassical approach based on the dephasing representation of quantum fidelity.
• Implementation of the accuracy test within existing molecular dynamics codes.
• Demonstration of feasibility using the photodissociation dynamics of carbon dioxide (CO2).

Main Results:

• The proposed semiclassical method effectively evaluates quantum dynamics accuracy.
• The method avoids the need for computationally intensive quantum dynamics simulations.
• Feasibility demonstrated through successful application to CO2 photodissociation dynamics.

Conclusions:

• The developed semiclassical method offers an efficient alternative for accuracy assessment in quantum dynamics.
• The method's ease of implementation in current molecular dynamics codes ensures wide applicability.
• This approach facilitates more accessible and cost-effective studies of molecular dynamics.