CALCULATION OF NUCLEAR MAGNETIC SHIELDINGS .11. VIBRATIONAL MOTION EFFECTS

Nuclear magnetic shieldings in first- and second-row hydrides were cal culated with electron correlation taken into account through third ord er. The calculation was performed using London's gauge-invariant atomi c orbitals (GIAOs) and finite-field Moller-Plesset perturbation theory (FF-MPPT). Furthermore, the vibrational motion corrections to the mag netic shieldings were evaluated. It was shown that the calculated isot ropic shielding constants at the experimental geometries are higher th an the experimental values, but that vibrational corrections are gener ally negative and improve the calculated shielding constants. (C) 1996 American Institute of Physics.