Performance of wave function and density functional methods for water hydrogen bond spin-spin coupling constants.
Spin-spin coupling constants in water monomer and dimer have been calculated using several wave function and density functional-based methods. CCSD, MCSCF, and SOPPA wave functions methods yield similar results, specially when an additive approach is used with the MCSCF. Several functionals have been used to analyze their performance with the Jacob's ladder and a set of functionals with different HF exchange were tested. Functionals with large HF exchange appropriately predict1JO H,2JH Hand2hJO Ocouplings, while1hJO His better calculated with functionals that include a reduced fraction of HF exchange. Accurate functionals for1JO Hand2JH Hhave been tested in a tetramer water model. The hydrogen bond effects on these intramolecular couplings are additive when they are calculated by SOPPA(CCSD) wave function and DFT methods. Graphical Abstract Evaluation of the additive effect of the hydrogen bond on spin-spin coupling constants of water using WF and DFT methods.
Departamento de Química Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain. garcia.delavega@uam.es.
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García de la Vega
Departamento de Química Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
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Omar
Departamento de Química Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
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San Fabián
DFT; Hydrogen bond; NMR; Spin–spin coupling constants