Dear CCL's; I 'd like to ask you how to calculate badn gap and excitation energies of open shell system. If anybody has some experiences about this matter using both ab initio and semiempirical methods would you please give some advices to me? I am looking forward to hearing from you soon. Yours Ohyun Kwon Department of Chemistry Auburn University Auburn AL 36849 USA email) kwonohy : at : mail.auburn.edu