Toward coupled-cluster accuracy in the prediction of nuclear shielding constants: a simple and efficient DFT approach

Exchange correlation functionals determined from energy criteria are not optimal for nuclear shielding predictions. We present a simple but highly efficient density functional theory (DFT) method which appears to correct for deficiencies in the virtual Kohn–Sham (KS) orbitals and eigenvalues. proach involves calculating the shieldings within the generalised gradient approximation using KS eigenvalues and orbitals from a conventional hybrid functional calculation including about 5% exact Hartree–Fock exchange. ielding parameters produced by these new functionals on first and second-row nuclei provide a dramatic improvement over conventional DFT functionals with an accuracy approaching coupled-cluster quality.