Ideas of Quantum Chemistry P70 shows how quantum mechanics is applied to chemistry to give it a theoretical foundation. The structure of the book (a TREE-form) emphasizes the logical relationships between various topics, facts and methods. It shows the reader which parts of the text are needed for understanding specific aspects of the subject matter. Interspersed throughout the text are short biographies of key scientists and their contributions to the development of the field. | 656 12. The Molecule in an Electric or Magnetic Field - I- H where Z is the magnetic moment operator of the corresponding particle. Why do we not have together with SH Hih in H1 the term Hlh . the interaction of the electron orbital magnetic moment with the field It would be so nice to have the full set of terms the spin and the orbital magnetic moments interacting with the field. Everything is fine though such a term is hidden in the mixed term resulting from 2m Pj cA 2. Indeed we get the Zeeman term corresponding Zeeman term from the transformation Pj Aj Aj Pj t H x rj pj H rj x pf mc J mc J 2mc J 2mc J H Lj -H -- Lj -H Morb el j 2mc 2mc where Morb ei j is according to the definition of eq. the orbital magnetic moment of the electron j. Next we have the terms - the electronic spin-orbit terms HHLS . the corresponding magnetic dipole moment interactions related to the term H3 in the Breit Hamiltonian. - the electronic spin-spin terms HSS . the corresponding spin magnetic moment interactions related to the term H5 in the Breit Hamiltonian. - the electronic orbit-orbit terms H11 . the electronic orbital magnetic dipole interactions corresponding to the term H2 in the Breit Hamiltonian . The terms H2 H3 H4 crucial for the NMR experiment correspond to the magnetic dipole-dipole interaction involving nuclear spins the term H5 of the Breit Hamiltonian . In more details these are the classical electronic spin-nuclear spin interaction H2 the corresponding Fermi contact term63 H3 and the classical interaction of the nuclear spin magnetic dipoles H4 this time without the contact term because the nuclei are kept at long distances by the chemical bond The magnetic dipole moment of a nucleus or electron feels the magnetic field acting on it through the vector potential Aj at the particle s position rj. This Aj is composed of the external field vector potential 2 H x rj - R . associated with the external magnetic field65 H the individual vector
