Calculations of hydrogen-bond-transmitted indirect nuclear spin–spin couplings: a comparison of density-functional and ab initio methods

Hydrogen-bond-transmitted indirect nuclear spin–spin coupling constants have been calculated by linear-response density-functional theory (DFT), coupled-cluster singles-and-doubles (CCSD) theory, and multiconfigurational self-consistent field (MCSCF) theory so as to benchmark the performance of DFT against the high-level ab initio methods. The systems under study are (NH3)2, (H2O)2, and (HF)2 and their charged counterparts N2H7+, H5O2+, and FHF−. In all cases, the 1hJ(XH) coupling through the X–H⋯Y hydrogen bond changes sign in the transition from the neutral to charged complex. As for intramolecular coupling constants, description of 1hJ(YH) and 2hJ(XY) by DFT deteriorates with an increasing number of lone pairs on the coupled nuclei.