Magnetic fields and density functional theory Page: 27 of 244
This thesis or dissertation is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
terms are the chemical shielding terms. The chemical shielding tensors are denoted
by 3. These terms contain in them the coupling between the electrons and each
nuclear spin separately with the applied field. These operators are still single spin
operators. The difference between these and the Zeeman terms is the electronic
coupling, hence these operators probe the electrons. The next to last term is the J
coupling, also known as the indirect spin-spin coupling. This is the coupling between
the two nuclei, which is manifest through the electrons. Unlike the first four operators,
this is a two spin operator. The last term is the dipolar coupling, or the direct spin-
spin coupling. The dipolar coupling does not involve electronic interactions. It is the
direct nuclei-nuclei interaction. As such it is mentioned here only for completeness.
These terms will be examined in more detail later. First, the connections between
the spin Hamiltonian and the full Hamiltonian should be made clear.
Perturbation theory is the method of choice as the interaction of the magnetic
fields with the electrons is much weaker than the electron-electron interaction. [6] A
molecular system may be considered as consisting of 2 weakly coupled subsystems.
The wavefunction for the full molecular system is 'I. The first system consists of the
electrons that feel a fixed scalar nuclear potential, the second contains the nuclei that
feel a uniform external applied field and the dipolar coupling. For simplicity, it is
easiest to consider only the chemical shielding at first as the remaining interactionsChapter 1. Introduction to Magnetic Fields
10
Upcoming Pages
Here’s what’s next.
Search Inside
This document can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Thesis Or Dissertation.
Salsbury Jr., Freddie. Magnetic fields and density functional theory, thesis or dissertation, February 1, 1999; Berkeley, California. (https://digital.library.unt.edu/ark:/67531/metadc709007/m1/27/: accessed May 6, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.