CALCULATIONS OF MAGNETIC-PROPERTIES .2. ELECTRON-CORRELATED NUCLEAR SHIELDING CONSTANTS FOR 9 SMALL MOLECULES

Calculations of the nuclear magnetic shielding constants at the self-consistent-field (SCF) and second-order Moller-Plesset (MP2) levels of theory are reported for H-2, N2, F2, HF, CO, HCN, HNC, H2O, and NH3. The reliability of the calculations is verified by the high degree of satisfaction of the appropriate sum rule. The second-order correlation corrections to the shielding constants are found to be particularly important for the multiply bonded atoms in molecules such as N2, CO, HCN, and HNC. Vibrational corrections to the shielding constants for the diatomic molecules are shown to be significant.