Solvent effects on the NMR parameters of H2S and HCN

A recently developed method to calculate singlet and tripler gauge-origin-i ndependent magnetic properties of solvated molecules is applied to the stud y of those parameters that determine an observed nuclear magnetic resonance signal: the magnetizability, the nuclear shieldings, and the indirect spin -spin coupling constants. The solvent is represented by a, dielectric mediu m and the electronic structure of the solvated molecule by Hartree-Fock and multiconfigurational Hartree-Fock wave functions. For the properties that depend on the external magnetic field, we use London atomic orbitals to ens ure gauge-origin independence and a rapid basis-set convergence. We find th at the dielectric-medium effects on these molecules are substantial, being of the same order as rovibrational and electron correlation effects, and th us cannot be neglected if accurate comparisons with liquid-phase measuremen ts are wanted. However, the present model is incapable of describing the cl ose-range interactions that may occur in solution. It, therefore, represent s the electrostatic effects of the bulk solvent, and the model is an initia l approach towards a complete nb initio model for the study of magnetic pro perties of solvated molecules. (C) 1999 John Wiley & Sons, Inc.