Theoretical Investigations of Molecular Electronic Structure in a Magnetic Field
AbstractMost available literature on molecular systems in magnetic fields are limited to special cases: Either small or highly symmetric species of specific orientation to the field, or fields of low intensity - or combinations of the above. This dissertation is devoted to the development, implementation, calibration, analysis and usage of computational quantum chemistry methods that are freed from such restrictions. Three research papers are presented. One deals with the inner workings of a generalized variant of Density Functional Theory which allows the magnetic field to be directly included (BDFT), and explores in depth how various functionals handle diamagnetic, paramagnetic and aromatic molecules. The second paper investigates the rich chemistry of the helium dimer in a strong magnetic field, thoroughly maps out the electronic structure of the molecule, and presents the many different magnetic bonding mechanisms and interactions that exist in this regime. The final paper revolves around application of highly accurate wave-function methods to determine the influence of terrestrially available magnetic fields on water. The work of this thesis presents important contributions to theoretical chemistry in the pres- ence of magnetic fields.
List of papers
|Paper I Kohn-Sham energy decomposition for molecules in a magnetic field. Sarah Reimann, Alex Borgoo, Jon Austad, Erik I. Tellgren, Andrew M. Teale, Trygve U. Helgaker and Stella Stopkowicz. Molecular Physics, 2019, volume 117, No. 1, pages 97 to 109. The paper is removed from the thesis in DUO due to publisher restrictions. The published version is available at: https://doi.org/10.1080/00268976.2018.1495849|
|Paper II Bonding in strong magnetic fields: role of spin and angular momentum. Jon Austad, Alex Borgoo, Erik I. Tellgren and Trygve Helgaker. Published as: Bonding in the helium dimer in strong magnetic fields: the role of spin and angular momentum. Physical Chemistry Chemical Physics, 2020, volume 22, pages 23502 to 23521. An author version is included in the thesis. The published version is available at: https://doi.org/10.1039/D0CP03259J|
|Paper III Effects of strong magnetic fields on water from rigorous quantum calculations. Hemanadhan Myneni, Dariusz Kedziera, Jan W. Andselm, Jon Austad, Erik I. Tellgren, Trygve Helgaker and Krzysztof Szalewicz. The preprint version of the paper is included in the paper.|