On the calculation of second-order magnetic properties using subsystem approaches in the relativistic framework

Malgorzata Olejniczak (1) , Radovan Bast (2) , Andre Severo Pereira Gomes (1)

1 PCMT - Physico-Chimie Moléculaire Théorique
2 High performance Computing Group

We report an implementation of the nuclear magnetic resonance (NMR) shielding (σ), isotope-independent indirect spin-spin coupling (K) and the magnetizability (χ) tensors in the frozen density embedding (FDE) scheme using the four-component (4c) relativistic Dirac--Coulomb (DC) Hamiltonian and the non-collinear spin density functional theory (SDFT). The formalism takes into account the magnetic balance between the large and the small components of molecular spinors and assures the gauge-origin independence of NMR shielding and magnetizability results. This implementation has been applied to hydrogen-bonded HXH⋯OH₂ complexes (X = Se, Te, Po) and compared with the supermolecular calculations and with the approach based on the integration of the magnetically induced current density vector. A comparison with the approximate Zeroth-Order Regular Approximation (ZORA) Hamiltonian indicates non-negligible differences in σ and K in the HPoH⋯OH₂ complex, and calls for a thourough comparison of ZORA and DC in the description of environment effects on NMR parameters for molecular systems with heavy elements.

Domaines: Chimie-Physique [physics.chem-ph]

Malgorzata Olejniczak, Radovan Bast, Andre Severo Pereira Gomes. On the calculation of second-order magnetic properties using subsystem approaches in the relativistic framework. Physical Chemistry Chemical Physics, 2017, 19, pp.8400-8415. ⟨10.1039/C6CP08561J⟩. ⟨hal-01442808⟩