The effect of hydrostatic pressure on g-tensor and hyperfine coupling constants of nitroxide radical characterized by ab initio calculations

A. Gurgenidze, A.I. Krylov, and S. Takahashi
J. Phys. Chem. Lett. , submitted (2025)

We present a computational study characterizing the effect of hydrostatic pressure on magnetic spin parameters, which enter the analysis of the electron paramagnetic resonance (EPR) spectra. EPR spectroscopy is a powerful tool for investigating the structures and dynamics of biological molecules. We report quantum-chemistry calculations of g-tensors and hyperfine coupling tensors (A-tensors) for the nitroxide radical spin label in the pressure range of 0-15 GPa. The hydrostatic pressure causes structural changes, which, in turn, result in the linear changes of the g- and A-tensors. The observed linear dependence of the g- and A-tensors suggests that these quantities can serve as reporters of a local pressure in complex environments. The corresponding simulated EPR spectra at the 9 GHz and 230 GHz reveal that the changes of EPR spectrum are more pronounced in the former. Our results indicate that the computational approach can address the challenge of determining magnetic spin parameters under extreme conditions, such as under high hydrostatic pressure.

Related Research

Computational studies of electronically excited and open-shell species: Jahn-Teller systems, radicals, diradicals and triradicals

Quantum information science