Trygve Helgaker

Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, Box 1033 Blindern, N-0315 Oslo, Norway

Video Recording

Abstract

In a strong magnetic field, chemistry changes: electronic states change their character, atoms and molecules change their shape, and their interactions with radiation are affected, often in a dramatic manner [1–8]. Perhaps most surprisingly, new bonding mechanisms occur, giving rise to molecules that do not exist on Earth but may exist elsewhere such as in the atmospheres of magnetic white dwarfs [4,5]. The exotic chemistry of atoms and molecules in strong magnetic fields provides a fresh perspective on the familiar chemistry on Earth; at the same time, it provides a stress test for quantum chemistry, whose methods have been developed for Earth-like conditions. Density-functional theory, for example, must be re-examined and adapted for the molecules in strong magnetic fields and such modifications have relevance also for the calculation of magnetic properties such as shielding constants and magnetizabilities [7].
In the talk, I give an overview of chemistry in strong magnetic fields and discuss the how the methods of quantum chemistry such as coupled-cluster theory [6] and density-functional theory [7] must be modified and adapted to study molecules and their electronic structure in magnetic fields.

Reference

[1] D. Lai, Rev. Mod. Phys. 73, 629 (2001)
[2] P. Schmelcher and W. Schweizer, eds. “Atoms and Molecules in Strong External Fields”, (Kluwer, 2002)
[2] E. I. Tellgren, A. Soncini and T. Helgaker, J. Chem. Phys. 129, 154114 (2008)
[3] E. I Tellgren, T. Helgaker and A. Soncini, Phys. Chem. Chem. Phys. 11, 5489–5498 (2009)
[4] K. K. Lange, E. I. Tellgren, M. R. Hoffmann and T. Helgaker, Science 337, 327–331 (2012)
[5] E. I. Tellgren, S. Reine, and T. Helgaker, Phys. Chem. Chem. Phys. 14, 9492 (2012)
[6] S. Stopkowicz, J. Gauss, K. K. Lange, E. I. Tellgren and T. Helgaker, J. Chem. Phys. 143, 074110 (2015)
[7] S. Reimann, A. Borgoo, J. Austad, E. I. Tellgren, A. M. Teale, T. Helgaker and S. Stopkowicz, Mol. Phys. 117, 97( 2019)
[8] C. Holzer, A. M. Teale, F. Hampe, S. Stopkowicz, T. Helgaker and W. Klopper, J. Chem. Phys. 150, 214112 (2019)