Diamagnetic contribution to the NMR magnetic shielding from QED theory

A. MALDONADO; G. AUCAR

Auckland

Congreso; World Association of Theoretical and Computational Chemists (WATOC) 2008; 2008

WATOC

One can define an object that have the same form within both the relativistic and the NR regime. It is based on the path integral formulation of Quantum Mechanics. Then the dynamical variable is not the wavefunction but the propagator itself. Polarization propagators are equivalent to double-time Green functions. They can be derived from bound-state QED as shown below. Main characteristic: a) the NR limit is obtained naturally as c  , b) there is no need to use restricted magnetic balance for relativistic calculations, c) electron correlation is included consistent with the order of the fluctuation potential inequations, d) results within NR domain shows that SOPPA or second order calculations are within the most reliables, e) dia and paramagnetic contributions are obtained as an approximation and goes to the same NR expressions, f) some of themost interesting physics that underlies the NMR spectroscopic parameters like the sign of J, the well-known Karplus rule, cooperativity effects, etc., can be fully explained.