Density fitted, local Hartree-Fock treatment of NMR chemical shifts using London atomic orbitals

An efficient program for calculating nuclear magnetic shielding tensors at the level of density fitted Hartree-Fock theory is presented. London atomic orbitals are used as AO basis functions, while ordinary Gaussians are employed as auxiliary fitting functions for the density fitting. The errors due to density fitting turn out to be very small. Accuracy and efficiency of the program are demonstrated in calculations on several test molecules.