MCSCF calculations of nitrogen NMR shielding constants using London atomic orbitals

Abstract

The MCSCF method is used to calculate the nitrogen shielding constants in HN 3 and four isomers of CH 2N 2. The calculations are performed using SCF and RAS SCF wavefunctions, in both cases using London atomic orbitals. For some of the shielding constants the correlation corrections exceed 100 ppm and lead to much closer agreement with experiment.