Calculation of nuclear magnetic shieldings. VIII. Gauge invariant many-body perturbation method.

The calculation of nuclear magnetic shieldings σ was performed for four first-row hydrides, i.e., HF, H2O, NH3, and CH4 using the finite-field many-body perturbation theory through second order in the electron correlation correction with London’s gauge invariant atomic orbitals. The calculated isotropic shieldings σ for the heavy atoms were larger than the experimental values. The rotational and vibrational correction for the σ of the F atom in HF at 300 K was estimated to be -4.0 ppm. [ABSTRACT FROM AUTHOR]