Evgeniy Yu. Pankratyev

How reliable are GIAO calculations of 1H and 13C NMR chemical shifts? A statistical analysis and empirical corrections at DFT (PBE/3z) level.

Reliability of calculated 1H and 13C NMR chemical shifts for various classes of organic compounds obtained with gauge‐invariant atomic orbital (GIAO) approach has been studied at the PBE/3ζ level (as implemented in PRIRODA code) using linear regression analysis with experimental data. Empirical corrections for the calculated chemical shifts δH,calc = δPBE/3ζ − 0.08 ppm (RMS 0.18 ppm, MAD 0.66 ppm) and δC,calc = δPBE/3ζ − 6.35 ppm (RMS 3.09 ppm, MAD 9.42 ppm) have been developed using the sets of 263 and 308 experimental values for 1H and 13C chemical shifts, respectively. The confidence intervals of NMR chemical shifts at 95% confidence probability are δH,calc ± 0.35 ppm for 1H and δC,calc ± 6.05 ppm for 13C.