A practical and efficient diabatization that combines Lorentz and Laplace functions to approximate nonadiabatic...

Area of Science:

• Quantum chemistry
• Computational physics
• Molecular dynamics

Background:

• Nonadiabatic coupling terms (NACTs) are crucial for understanding molecular dynamics, especially in systems with conical intersections.
• Accurate calculation of NACTs often requires extensive computational resources.
• Existing methods for approximating NACTs can be computationally demanding.

Purpose of the Study:

• To develop a more efficient and straightforward method for calculating nonadiabatic coupling terms.
• To establish a fixed relation between parameters of Lorentz and Laplace functions for approximating NACTs.
• To simplify the construction of diabatic states and their couplings.

Main Methods:

• A fixed relation (α × β = 1.397) was established between α and β parameters of Lorentz and Laplace functions.
• The geometric average of potential couplings was used to determine the mixing angle for constructing diabatic states.
• The method was tested on one-dimensional LiF and two-dimensional collinear NH3Cl systems.

Main Results:

• The developed method significantly reduces the number of geometries needed for NACT computation.
• The approach streamlines the construction of diabatic states and inter-state couplings.
• Promising results were obtained for both LiF and NH3Cl test systems.

Conclusions:

• The new method offers a computationally efficient and simplified approach to calculating NACTs.
• This technique facilitates the study of nonadiabatic processes in molecular systems.
• The method shows potential for broader application in computational chemistry and physics.