Hydrogen bond studies. 71. Ab initio calculation of the vibrational structure and equilibrium geometry in HF2 and DF2

MO LCAO SCF calculations have been performed to investigate the molecular astructure and vibrational spectrum of the bifluoride ion in its normal and deuterated form. The potential energy for nuclear motions has been evaluated as a function of the molecular degrees of freedom, taking only linear geometries into account. The vibrational Schrödinger equation has been solved by expanding the vibrational part of the total wavefunction as a sum of products of linear harmonic-oscillator eigenfunctions. The calculated properties are in good agreement with experiments, and even the minute effects of deuteration are well reproduced.