Knowledge Bank

The measurements were recorded with a grating vacuum Spectrometer in which observations were made in first order for the 2900 to $3350cm-1$ region at a resolution of $\sim 0.07$ $cm-1$ and in second order above $3350cm-1$. The $H216O/H217O$ set of data were of samples containing; 64.2% $H216O,34.9$ and $0.9$. From this set of data plus line positions measurements of $H218O$ and $H217O$ given by Toth et $al.1$ for the 1.9$\mu m$ region and the pure rotational spectrum given by Kauppinen and Kyr$\prime ‘o,2$ ground state energy levels were determined. The ground state levels were then used to determine energy levels in the (020), (100) and (001) states for both molecules as well as a re-determination of the levels in the (011) and (110) states, which, in turn, were used obtain energy levels in the (010) state from ``hot’‘ band transitions observed in this work. In light of the new set of ground state levels, the measurements reported by Williamson et $al.3$ in the (010) band were re-examined to determine a new set of levels in the (010) state for $H216O$ and to establish a set of levels in the (010) state of $H212O$. Another set of data on $H216O$ were recorded in order to obtain line strength measurements in the (020), (100)and (001) bands. In all, 822 absorptions were measured from which line strengths were obtained by the equivalent width method. They were fitted by the method already applied to earlier measurements of $H2616O$ in this spectral $region.4$ Also included were measurements of saturated lines from which self-broadening coefficients could be obtained. The $H216/H217O$ set of data were also measured to obtain line strengths and analyzed in the same manner as the $H216O$ data.