Knowledge Bank

In view of the importance of $NH3$ in the atmospheres of the major planets, there is a need for knowledge of the optical constants for $NH3$ in condensed states. We have attempted to obtain these constants for solid $NH3$ by quantitative measurements of the spectral absorptance. The Lambert absorption coefficients for solid $NH3$ from 5200 - $970cm-1$ were determined by the method used in our earlier study of $water.1$ The imaginary part $ni$ of the refractive index was determined directly from the Lambert coefficients. Values of $nr$ can be determined from an analysis of the spectral absorptance using the Kramers-Kronig relations.