Nuclear Magnetic Resonance: Volume 39 (Specialist Periodical Reports, Volume 39),Used

Excerpt. Reprinted by permission. All rights reserved.Nuclear Magnetic Resonance Volume 39A Review of the Literature Published Between January 2008 and May 2009By G. A. Webb, K. KamienskaTrela The Royal Society of ChemistryCopyright 2010 The Royal Society of ChemistryAll rights reserved.ISBN: 9781847550606ContentsPreface G. A. Webb and K. KamiennskaTrela, v,Books and reviews W. Schilf, 1,Theoretical and physical aspects of nuclear shielding Cynthia J. Jameson and Angel C. De Dios, 42,Applications of nuclear shielding Shigeki Kuroki, Shingo Matsukawa and Hidekazu Yasunaga, 70,Theoretical aspects of spinspin couplings Hiroyuki Fukui, 151,Applications of spinspin couplings Krystyna KamienskaTrela and Jacek Wjcik, 179,Solid state NMR spectroscopy A. E. Aliev and R. V. Law, 227,NMR of proteins and nucleic acids P. J. Simpson, 268,NMR of carbohydrates, lipids and membranes Elizabeth F. Hounsell, 290,Synthetic macromolecules Hiromichi Kurosu and Takeshi Yamanobe, 322,NMR in living systems M. J. W. Prior, 363,Nuclear magnetic resonance imaging Tokuko Watanabe, 398,NMR of liquid crystals and micellar solutions Gerardino D'Errico and Luigi Paduano, 424,Oriented molecules K. V. Ramanathan, Nitin P. Lobo and C. L. Khetrapal, 456,CHAPTER 1Theoretical and physical aspects of nuclear shieldingCynthia J. Jameson and Angel C. De DiosDOI: 10.1039/9781849730846000421. Theoretical aspects of nuclear shielding1.1 General theorySeveral methodologies are being developed for including relativistic effects in the calculation of molecular magnetic properties, in particular the nuclear magnetic shielding tensor. Approaches used can be grouped as follows: fourcomponent or fully relativistic, twocomponent or quasirelativistic, and perturbational. Volume 36 of this series gives an overview and newer developments have been discussed in succeeding volumes. In the fourcomponent relativistic treatment of nuclear shielding, the Dirac operator is linear with respect to the vector potential such that the second order energy consists only of a single term, the paramagnetic term, when the first order wave function is directly expanded in the full space of unperturbed states. This standard linear response theory has been used by several groups. Alternative formulations of fourcomponent treatments of nuclear magnetic properties including shielding have been proposed by Kutzelnigg and others by explicitly incorporating the magnetic balance condition between the small and large components of the Dirac spinor in the presence of magnetic fields. But, is it mandatory to resort to a magnetically balanced basis set for calculations of magnetic properties with perturbative fully relativistic methods? Calculations of molecular properties using finite basis sets in relativistic quantum mechanics are contaminated with spurious states. In order to eliminate them, kinetically balanced basis sets were suggested. Kutzelnigg has shown that the exact relativistic wavefunction of the ground state of Hlike ions is expandable in a kinetically balanced eventempered Gaussian basis. Two kinetically balanced bases have previously been investigated, restricted kinetic balanced (RKB) and unrestricted kinetic balanced (UKB). In this reporting period, the application of different kinetic balance prescriptions using the fourcomponent polarization propagator approach in the calculation of nuclear magnetic shielding were investigated. They find that working with relativistic polarization propagators there is no formal requirement to enforce the application of magnetic kinetic balance prescription. On the contrary, the RKB prescription is found to be a necessary condition, but is not enough to obtain reliable results. The kinetic balance prescription ensures that the matrix representation of the kinetic energy operator of the unperturbed system will properly be described in the nonrelativistic limit. Both the RKB and the UKB prescriptions we