Calculation of the fourth-rank nuclear magnetic hypershielding of some small molecules

G. I. PAGOLA; M. C. CAPUTO; M. B. FERRARO; P. LAZZERETTI

PHYSICAL REVIEW A - ATOMIC, MOLECULAR AND OPTICAL PHYSICS

AMER PHYSICAL SOC

Año: 2006 vol. 74 p. 22509 - 22509

1050-2947

A computational scheme has been implemented to evaluate magnetic hypershielding at the nuclei of a molecule in the presence of an external spatially uniform, time-independent magnetic field, accounting for cubic response contributions via Rayleigh-Schrödinger perturbation theory. Numerical estimates have been obtained for hydrogen and heavier atoms in H2, HF, H2O, NH3, and CH4 molecules at the coupled Hartree-Fock level of accuracy within the conventional common-origin approach. Gaugeless basis sets of increasing size and flexibility have been employed in a numerical test, to estimate the degree of convergence of theoretical tensor components. A further test for convergence has been carried out by evaluating properties for two different coordinate systems.