On a Perturbed Hartreehyphen;Fock Study of the Magnetic Susceptibility and the13C and17O NMR Shielding Constants in Formaldehyde with Slater Basis Sets

摘要

The theoretical study of Flygareet al.on onehyphen;electron properties of the formaldehyde molecule is extended to include the paramagnetic susceptibility and the13C and17O NMR shielding constants and to investigate their sensitivity to Slater basishyphen;set quality. The Gaussian transform method is used to evaluate the necessary integrals. Using the fully coupled perturbed Hartreehyphen;Fock formalism, we find that improvements in the wavefunction produce significant changes in most components of the secondhyphen;order properties. The best shielding calculations, obtained with a doublehyphen;zeta Slater set, are within the rather large experimental uncertainties, whereas the agreement between the theoretical and experimental susceptibility results is less satisfactory. The complete paramagnetic tensors are analyzed in terms of MO and AO contributions. Comparisons are made with otherab initiocalculations and with simplified forms of the theory.