Knowledge Bank

The triply degenerate bend $(\nu 4)$ of $NH4+$ has been studied by velocity modulation diode laser spectroscopy. 90 lins have been measured, about 30% of which have been assigned to low-J P and R branch transitions. Preliminary analysis yields a band origin of $1397\pm 1cm-1$, and suggests strong Coriolis coupling between $\nu 2$ and $\nu 4$. A least squares fit to an effective spherical rotor Hamiltionian is in progress.