title: Influence of Density Functionals and Basis Sets on One-Bond Carbon-Carbon NMR Spin-Spin Coupling Constants.
abstract: The basis set and the functional dependence of one-bond carbon-carbon NMR spin-spin coupling constants (SSCC) have been analyzed using density functional theory. Four basis sets (6-311G**, TZVP, EPR-III, and aug-cc-pVTZ-J) and four functionals (PBE, PW91, B3LYP, and B3P86) are tested by comparison with 70 experimental values corresponding to 49 molecules that represent multiple types of hybridization of the carbon atoms. The two hybrid functionals B3P86 and B3LYP combined either EPR-III or aug-cc-pVTZ-J basis sets lead to the best accuracy of calculated SSCC. However, a simple linear regression allows for the obtaining of scaled coupling constants that fit much better with the experimental data and where the differences between the different basis sets and/or functional results are significantly reduced. For large molecules the TZVP basis set can be an appropriate election presenting a good compromise between quality of results and computational cost.
authors.affiliation: Departmento de Química Física, Facultad de Química, Universidad de la Habana, La Habana 10400, Cuba, and Departmento de Química Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Suardíaz
authors.affiliation: Departmento de Química Física, Facultad de Química, Universidad de la Habana, La Habana 10400, Cuba, and Departmento de Química Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Pérez
authors.affiliation: Departmento de Química Física, Facultad de Química, Universidad de la Habana, La Habana 10400, Cuba, and Departmento de Química Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Crespo-Otero
authors.affiliation: Departmento de Química Física, Facultad de Química, Universidad de la Habana, La Habana 10400, Cuba, and Departmento de Química Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: García de la Vega
authors.affiliation: Departmento de Química Física, Facultad de Química, Universidad de la Habana, La Habana 10400, Cuba, and Departmento de Química Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Jesús San
authors.initials: JS
authors.lastname: Fabián