"Paulo E. Abreu" wrote: > > What do you mean by a legitimate physical phenomenom ? Can you detect it > experimentally ? Yes, you can: hybridization changes the charge distribution which is, in principle observable I. B. -- Dr. Isaac B. Bersuker Institute for Theoretical Chemistry Department of Chemistry & Biochemistry The University of Texas at Austin Austin, TX 78712, USA Ph: (512) 471-4671 Fax: (512) 471-8696 Email: bersuker \\at// eeyore.cm.utexas.edu