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Study of Protein Dynamics via Neutron Spin Echo Spectroscopy

Study of Protein Dynamics via Neutron Spin Echo Spectroscopy

Published on: April 13, 2022

Surface hopping trajectory simulations with spin-orbit and dynamical couplings.

Giovanni Granucci¹, Maurizio Persico, Gloria Spighi

¹Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via Risorgimento 35, 56126 Pisa, Italy.

The Journal of Chemical Physics

|December 20, 2012

Summary

This study examines spin-orbit interactions in molecular dynamics simulations for spin-forbidden transitions. It compares spin-diabatic and spin-adiabatic methods, highlighting the spin-adiabatic approach

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Area of Science:

Computational Chemistry
Quantum Mechanics
Molecular Dynamics

Background:

Surface hopping simulations are crucial for modeling chemical dynamics.
Spin-forbidden transitions require accurate treatment of spin-orbit coupling.
Existing methods for incorporating spin-orbit effects have limitations.

Purpose of the Study:

To evaluate two distinct approaches for including spin-orbit interaction in surface hopping simulations.
To analyze the strengths and weaknesses of spin-diabatic and spin-adiabatic methods.
To provide insights into simulating spin-forbidden transitions accurately.

Main Methods:

Comparison of spin-diabatic and spin-adiabatic approaches in surface hopping molecular dynamics.
Utilizing eigenstates of spin-free and total electronic Hamiltonians.
Analysis of spin-orbit coupling effects on transition dynamics.

Main Results:

The spin-diabatic approach, using spin-free eigenstates, shows inconsistencies, particularly with multiple spin multiplets.
The spin-adiabatic approach, based on total electronic Hamiltonian eigenstates, offers an alternative.
Both methods' advantages and disadvantages are discussed.

Conclusions:

The spin-adiabatic method is presented as a potentially more consistent approach for spin-orbit interactions in surface hopping.
Careful consideration of the chosen method is essential for accurate simulation of spin-forbidden transitions.
The study provides a comparative analysis to guide future research in the field.