Status of molecular opacities of interest in the modeling of a proto-solar nebula

The report centers on general procedures applicable to the calculation of constitutive properties (equation of state and opacity) of media that serve as models for the solar nebula during planet formation and for the atmospheres of some planets. Specifically considered are the equilibrium compositions of a mixture of atoms, molecules, and their ionic species in the gaseous phase, condensation into grains with refractory cores and mantles of volatile compounds, and the 'optical' properties of the grain-gas medium. A summary of available and still needed basic (input) data and some currently available results are presented. (Auth.)