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

Calculations of the nuclear magnetic shielding constants at the self-c onsistent-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. T he reliability of the calculations is verified by the high degree of s atisfaction of the appropriate sum rule. The second-order correlation corrections to the shielding constants are found to be particularly im portant 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.