This award will support collaborative research between Drs. Jeffrey Stephens and Vincent McCoy, California Institute of Technology and Dr. Christian Jungen, Laboratoire de Photophy- sique Moleculaire, University of Paris, Orsay, France. The objective of the research is to study the dynamics of highly excited molecular electronic states. The investigators propose to develop methods of electronic structure calculation, which are particularly appropriate for the study of dynamics of highly excited bound states molecules, including their photoelectron spectroscopy. The proposed research is relevant to recently developed and future experimental techniques, which probe highly excited molecular states via selective laser excitation. The physical basis of the method singles out the description of short-range particle (nuclei and electrons) correlations, which are ultimately responsible for the evolution and decay of a highly excited molecular complex. The proposed research connects in a unified manner with multichannel quantum defect theory (MQDT), which has been largely developed over a period of years for the purpose of describing and predicting the evolution and decay of highly excited molecular complexes. The suggested approach provides for initial development of the technique and ab initio calculation of fundamental interaction parameters needed to exploit the power of MQDT. The results of this project will be of fundamental interest and direct relevance to researchers currently developing modern experimental spectroscopies in the US and Europe. The project will benefit from the complementary expertise of the two research groups. The French collaborator Dr. Jungen is an internationally recognized expert in the area of MQDT and molecular structure theory. The US research team has a strong background in the area of ab initio computation of molecular Rydberg and continuum states.
