A publication of PCMT team makes it to the cover of the special issue of International Journal of Quantum Chemistry on "Quantum Embedding Electronic Structure Methods"

The use of quantum embedding methods to determine and analyze molecular properties such as response to an external magnetic field, makes the cover of the International Journal of Quantum Chemistry.

In this study jointly conducted by Małgorzata Olejniczak (Centre of New Technologies, Poland), Loïc Halbert, Valérie Vallet and André Severo Pereira Gomes (PCMT, PhLAM) the "Frozen density embedding" (FDE) method is used to study of the effects of solvent on NMR shielding for a system containing a heavy element (molybdenum in a molybdate ion, MoO42-).

In this study it was shown that the FDE method, combined with 2 or 4 component relativistic Hamiltonians, allows NMR shielding calculations for solvated systems with a very good accuracy, and this with a much reduced computational effort compared to standard quantum approaches (DFT for a solute and solvent molecules), which makes it possible to take into account a very large number of structural configurations, necessary to describe temperature effects. 

This work has led to an understanding of the relative importance of direct (changes in the electronic structure due to interactions such as hydrogen bonding) and indirect (change in the structure with respect to the gas-phase structures) effects on NMR shielding. 

In addition, by presenting a detailed analysis of how shielding tensors change spatially as water molecules solvate the molybdate ion, it was possible to establish that, while the operators associated with NMR shielding are very short-range, the solvent-induced perturbations are felt far beyond the environment close to the molybdate atom.

Reference:

Loïc Halbert, Małgorzata Olejniczak, Valérie Vallet, André Severo Pereira Gomes
Investigating solvent effects on the magnetic properties of molybdate ions (MoO42-) with relativistic embedding

Int. J. Quantum Chem. 2019, e26133

DOI: 10.1002/qua.26207

Liens:

http://dx.doi.org/10.1002/qua.26207

https://hal.archives-ouvertes.fr/hal-02413336

Cover of the International Journal of Quantum Chemistry Special Issue: Quantum Embedding Electronic Structure Methods