Figure 5.

Plots of ${\delta }_{-}$ vs. ${\gamma }^{\left(\omega \right)}$ for the series of isotopologues of H${}_2$O, SO${}_2$, and O${}_3$. A clear linear trend was obtained in all systems. The fundamentals needed to obtain the parameters were obtained from the references indicated: water [55,56,57], sulfur dioxide [58], and ozone [49]. The force constants were obtained from the principal isotopologues.