Scaled DFT chemical shieldings

• Published in: Chemical physics letters Vol. 380; no. 3; pp. 251 - 257
• Main Author: Chesnut, D.B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 21.10.2003; Elsevier Science
• Subjects: Atomic and molecular physics; Calculations and mathematical techniques in atomic and molecular physics (excluding electron correlation calculations); Density-functional theory; Electronic structure of atoms, molecules and their ions: theory; Exact sciences and technology; Molecular properties and interactions with photons; Nuclear resonance and relaxation; Physics; Sulfur compounds; Phosphorus compounds; Paramagnetism; Nitrogen compounds; Theoretical study; Oxygen compounds; Screening; Density functional method; Fluorine compounds; Ab initio calculations; Excitation energy; Nuclear magnetic resonance; Carbon compounds
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2003.08.104

A constant scaling reducing the paramagnetic component of chemical shieldings at the B3LYP/6-311+G(2d or d, p)//B3LYP/6-311+G(d, p) level is able to reproduce experimental results in a way that improves upon other density functional methods and rivals more sophisticated ab initio approaches. Root-mean-square errors (rmse) for carbon, nitrogen, oxygen, fluorine, phosphorus, and sulfur are found to be 2.3, 7.9, 13.2, 15.9, 22.1, and 29.7 ppm, respectively; the rmse expressed as a percentage of the shielding range varies from 1.1% to 3.2%. Anisotropies are also well reproduced. The reduction in the paramagnetic term can be associated with a constant scaling increase of the excitation energies.