Knowledge Bank

Half-widths and shapes of several rotational lines in $\nu 2$-bands of ammonia, collision-broadened by hydrogen, have been measured, at room temperature, with a spectral resolution of $0.15m-1$. Line intensities and self-broadened half-widths have also been measured. From the line intensity data, an estimate of $Sband=600\pm 30$ $cm-2$ $atm-1$ has been derived for the absolute intensity of the pair of bands. Hydrogen-broadened half-widths have been found to be $0.075\pm 0.004$ $cm-1$ $atm-1$ for all the lines measured. Shapes of the lines in $NH3-H2$ collisions seem to conform to the super-Lorentz line shape proposed by Varanasi et al. for dipole-quadrupole collisions.