The Drude model for treating the interaction of excess electrons with polar molecules 
is extended to calculate continuum functions and to evaluate photodetachment cross sections.  
The approach is applied to calculate the cross sections for photodetachment of dipole-bound 
electrons from HCN-and HNC-.  In addition, an adiabatic model separating the angular and 
radial degrees of freedom of the excess electron is introduced and shown to account in 
a qualitative manner for the cross sections.