Diamagnetic contribution to the NMR magnetic shielding from QED theory

ALEJANDRO MALDONADO Y GUSTAVO A. AUCAR

Auckland

Simposio; WATOC 2008 - Satellite Meeting; 2008

New Zealand Institute for Advanced Study

Diamagnetic contributions to NMR magnetic shieldings from QED theoryAlejandro Maldonado and Gustavo A. AucarPhysics Department - Natural and Exact Faculty - Northeastern University of ArgentinaRecently few derivations of NMR spectroscopic parameters from QED theory were published. One of them arises as a generalization of time-dependent response theory [1] and another was based on perturbative S-matrix formulation of bound-state QED [2].In line with the last formulation a new model was proposed which shows its relation with therelativistic polarization propagator approach. This has the advantage of being related to a wellknown formalism mostly applied on relativistic quantum chemistry; and the fact that all QEDcorrections can be included within the DIRAC code [3].We will show in this poster presentation two recent developments based on the last formalism: a)the reason why the whole diamagnetic contribution to magnetic shieldings arise from an interval ofexcitation energies, and b) the radiative corrections to the diamagnetic (and paramagnetic for raregases) term of nuclear magnetic shieldings.1. R. H. Romero and G. A. Aucar, Phys. Rev. A 65, 053411 (2002).2. R. H. Romero and G. A. Aucar, Int. J. Mol. Sci. 3, 914 (2002).3. DIRAC, H. J. Aa. Jensen, T. Saue, L. Visscher et al.(http://dirac.chem.sdu.dk).