CCL, I was wondering if anyone had any experience looking at or for dative bonds using Gaussian and the NBO analysis. thanks in advance. Steven D. Bennett University of Delaware Department of Chemistry 304A Drake Hall (302) 831-8720 sbennett "-at-" wotan.duch.udel.edu (302) 737-8485 http://udel.edu/~sbennett/ "X rays are a hoax" Lord Kelvin