Vol. 16, issue 04, article # 3

Abstract:

Line strengths of weak H₂O rotation-vibration lines in the near UV region at 0.27 mkm were estimated using the Partridge and Schwenke variational calculations of water vapor absorption spectrum from 0 to 20000 cm^-1 that were then extrapolated to 40000 cm^-1. It was found that transition strengths within the ground electronic state of the Н₂О molecule are close to 10^-9 сm^-2 atm^-1, and they cannot explain the absorption observed experimentally. The qualitative analysis of interaction between the ground and excited states was performed, and it was shown that the centrifugal distortion nearby the HOH linear configuration may lead to a considerable (up to 1%) mixing of rotation-vibration-electronic wave functions. As a result, transitions to the high-excited vibration states within the ground electronic state such as (0V0) become quite intense.