Anabinitiosemirigid bender calculation of the rotation andtranshyphen;tunneling spectra of (HF)2and (DF)2

摘要

Using a purelyabinitiominimum energy path for thetranshyphen;tunneling motion in the HF dimer, the energy levels for theKhyphen;type rotation andtranshyphen;tunneling motion for (HF)2and (DF)2are calculated with a onehyphen;dimensional semirigid bender Hamiltonian and no adjustable parameters. The transition moments for rotationhyphen;tunneling transitions are calculated, using ourabinitiovalue for the dipole moment of an isolated HF molecule, and we also calculateBmacr; values. The energy levels we obtain are in close agreement with experiment; for example, theK=0 tunneling splitting in (HF)2is calculated as 0.65 cmminus;1compared to the experimental value of 0.658thinsp;69 cmminus;1. As well as showing that ourabinitiominimum energy path is very good, the calculation demonstrates that the semirigid bender formalism is able to account quantitatively for the unusualKdependence of the rotational energies resulting from the quasilinear behavior, and that thetranshyphen;tunneling motion is separable from the other degrees of freedom. We use the results to predict the locations, and transition moments, of the Dgr;K=0 and plusmn;1 subbands in the tunneling spectra of (HF)2and (DF)2, many of which have not yet been observed.