Knowledge Bank

The direct numerical diagonalization (DND) $method1$, which has achieved considerable success with calculations for $CO2$, is now being applied to calculations of line position and intensity for the water molecule. The basis functions utilized by $Johnson2$, the bisector valence coordinate Hamiltonian developed by Carter, Handy, and $Sutcliffe3$, and the potential function calculated by $Jensen4$ have been combined with the direct product expansion approach of DND. Comparisons will be given between Jensen’s potential function, expanded around the equilibrium angle, and a preliminary potential function, expanded around linearity. Comparison of our calculations with previous investigators and observations will be given with respect to line intensity as well as line position $data.1$R. B. WATTSON AND L. S. ROTHMAN, J. Mol. Spectrosc. 119, 83-100 (1986). $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$B. R. JOHNSON AND W. P. REINHARDT, J. Chem. Phys. 85, 4538-4556 (1986). $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}$S. CARTER, N. C. HANDY, AND B. T. SUTCLIFFE, Mol. Phys. 49, 745-748 (1983). $\mathrm{<mrow\; data-mjx-texclass="ORD">4</mrow>}$P. JENSEN, J. Mol. Spectrosc. 133, 438-460 (1989).