Struct. Chem. 21, 755-759 (2010)

DOI: 10.1007/s11224-010-9608-8

Influence of the basis set on the calculation of the absolute 13C shieldings of methyl derivatives (CH3X with X = CH3, CN, NH2, NO2, OH, F) with special emphasis in the cases of X = Cl, Br, SH, SeH, and PH2
Within the set of 13 methane derivatives, the best results concerning 13C absolute shieldings were obtained using the GIAO/MP2/6-311++G(d,p) or the GIAO/MP2/aug-cc-pVTZ approximations. An important finding is that the deviations found with the GIAO/B3LYP/6-311++G(d,p) approach appears to be related to the atomic weight of the X atom in CH3X: the higher the atomic weight the larger the deviation.