Professor John S. Dahler is supported by a grant from The Theoretical and Computational Chemistry Program to develop a theory of laser-induced collision processes. Experimental studies have demonstrated the fact that reactions which occur in colliding molecular beams are influenced by the presence of laser fields to the extent that laser-induced association depends on the polarization of the laser light. This research has a potential long term impact in furthering our understanding of laser-induced chemistry. Dahler will develop theories to explain experimental observations in the following areas: 1) field free associative and Penning ionization which occurs in molecular beam collision experiments; 2) the effects of polarization on chemi-ionization and laser-induced excitation transfer processes; and 3) the characteristics of transiently populated quasi-molecular states produced during laser-induced collisional processes. Dahler will also develop the necessary numerical and computational methods to perform computer simulations in support of these theoretical developments.