Dicke narrowing as an example of line mixing

In the preceeding paper it was shown that the general problem of spectral line shapes in multiline, IR spectra may be determined by solving a transport relaxation equation far the off-diagonal elements of the density matrix. This is a semiclassical equation at the Wang-Chang-Uhlenbeck level, i.e., it treats the quantized internal states as nondegenerate. Hen we apply the master equation to the case of Dicke narrowing, and by discretizing the velocity distribution show that Dicke narrowing of a single line may be treated in exactly the same manner as line mixing. Both effects lead to a narrowing of a spectral distribution. We indicate how the numerical technique can be extended and used to calculate profiles in the general case of spectra with speed-dependent broadening, shifting, and line mixing. [S1050-2947(99)11305-2].