SCF-MO-LCGO calculations are performed for H502+ as a model illustrating the properties of a symmetrical hydrogen bond with a double-minimum potential well. The potential curves for the proton in the hydrogen bond with and without electrical fields for various 0-0 distances are calculated, along with the dipole moments, polarizabilities, hyperpolarizabilities, and transition moments of the OH stretching vibrations in the hydrogen bond. The total dipole moment is almost twice as large as the contribution of the proton alone for displacements which are not too large. The relation between the dipole moment and the displacement cannot be approximated linearly. Thus hyperpolarizabilities are of importance. The most important result obtained is that the polarizability is about two orders of magnitude larger than usual polarizabilities. The polarizability of unsymmetric hydrogen bonds may also be considerably larger. The large polarizability causes three interaction effects: an interaction between symmetrical hydrogen bonds via proton dispersion forces, an induced-dipole interaction of the hydrogen bonds with the anions and the dipole fields of the solvation molecules, and an interaction between the transitions in the hydrogen bond and other, especially the intermolecular, vibrations. These interactions cause the strong continuous absorption which is observed in the ir spectra with liquid systems containing such hydrogen bonds. The smaller polarizability of unsymmetrical hydrogen bonds causes band broadening.A continuous absorption was observed in the infrared spectrum on investigating acid and base solutions in the range of the fundamental vibrations1 2 and in the range of the overtones,3•4 567as well as with acidic and basic polyelectrolytes.5-8 This is caused in the acid solutions by H502+ groupings and with bases by H302_ groupings.8 The continuum is not only observed in the presence of these bonds between water molecules

described in terms of hydrogen atoms. Oxygens terminated with H atoms are not considered as models of the terminal hydroxyl groups of the zeolite but as skeletal oxygens which are described less adequately by the model.It is further assumed that the charges on the skeletal oxygens are correct then the error on oxygens terminated by hydrogen atoms is about 0.1e0, i.e., about 20%. The error in the charges and further calculated characteristics of the skeletal oxygens and of the Na, Si, and A1 atoms, resulting from the imperfection of the zeolite model used, is probably much lower.

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SCF‐M0‐LCGO‐Berechnungen für H5O; als Modell, das die Eigenschaften einer symmetrischen Wasserstoffbindung mit einem Doppelminimum‐Potentialtopf besitzt, werden durchgeführt.

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