IMPROVEMENTS IN THE VIBRATION INTERVAL PREDICTIONS FOR $H_{3}^{+}$

$^{1}$C. E. Dykstra and W. C. Swope, J. Chem. Phys. 70, 1 (1979).Author Institution: Department of Chemistry, Allegheny College; Department of Chemistry, Spectral Science Incorp.This study reports an excellent least squares curve fit of Dykstra and Swope’s ab-initio $H^{+}_{3}$ potential energy $surface^{1}$. The curve fit function is a sixth degree symmetry adapted polynominal expressed in the variables $\rho_{i} - (R_{i} - R_{eq})R_{i}$ with equilibrium bond length $R_{eq}$ and instantaneous bond lengths $R_{i}$. Vibration energies are determined using variational methods, and the theoretical and available experimental excitation energies for $H^{+}_{3}, D^{+}_{3}, H_{2}D^{+}$, and $D_{2}H^{+}$ agree to within $2 cm^{-1}$