Chemical Reaction Rates for Systems with Spin-Orbit Coupling and an Odd Number of Electrons: Does Berry's Phase Lead to Meaningful Spin-Dependent Nuclear Dynamics for a Two State Crossing?

TL;DR

This paper explores how Berry's phase influences spin-dependent nuclear dynamics in nonadiabatic reactions with spin-orbit coupling, revealing significant spin polarization effects in non-linear molecular geometries.

Contribution

It demonstrates that Berry force can induce notable spin polarization in reaction products when molecular geometry is non-linear and the Hamiltonian is complex.

Findings

Significant spin polarization occurs in non-linear geometries with non-zero Berry force.

Berry's phase impacts nuclear motion in gas phase reactions with spin-orbit coupling.

Implications for spin selectivity in chemical reactions are discussed.

Abstract

Within the context of very simple avoided crossing, we investigate the investigate the effect of a complex diabatic coupling in determining spin-dependent rate constants and scattering states. We find that, if the molecular geometry is not linear and the Berry force is not zero, one can find significant spin polarization of the products. This study emphasizes that, when analyzing nonadiabatic reactions with spin orbit coupling (and a complex Hamiltonian), one must consider how Berry force affects nuclear motion -- at least in the context of gas phase reactions. Work is currently ongoing as far as extrapolating these conclusions to the condensed phase where interesting spin selection has been observed in recent years.