Berechnung der isotropen Kopplungskonstanten für die Wechselwirkung zwischen den Kernspins inHD

The coupling constant is calculated by using several basis sets of Gaussian functions differing in size and parameters. For the first time the result of 42.40 cps is in very satisfactory agreement with experiment (42.7?+0.5 cps). The calculations justify our conclusions that 1^st one has to determine classes of excited states which are complete respective to the chosen basis set, 2^d the restriction to the class of singly excited states is adequate and 3^d correlation effects must be included but a perturbational approach is sufficient. These restrictions are essential for handling large basis sets which makes our method transferable to larger molecules.