Subject: Question on ionization potentials.

From: Carolina <[email-masked]>
Date: Fri, 20 Aug 93 21:37:21 CDT

Dear netters:

	I am doing my summer proyect and I came along with something
	that I can not understand. I have calculated with a semiempirical
	method a few molecular properties, such as charges, ionization
	potentials and frontier orbitals of some molecules.

	The set of molecules I have worked on are neutral, but can also
	be calculated as charged species, since they contain several
	sulfate or phosphate groups.

	The neutral species have ionization potentials about -10 eV, 
	those moderately charged have ionization potentials about
	-0.05 eV, but fully charged molecules give me ionization
	potentials of +20 eV if I follow Koopman's theorem.

        I know that neutral species of these molecules exist since I
	have a sample in my hands now, and I know that partially charged
	molecules also exist since I can tritrate them, but ....

	This is my question since I am not a theoretician!!!

	Could the fully charged molecules exists at all?. If am correct
	the ionization potential predicts that they won't.

	Any comments will be wellcome, since they will help me to write
	my report.

	With many thanks,
--

___________________________________________________________________
			CAROLINA GODOY-ALCANTAR
Facultad de Ciencias
Universidad del Edo. de Morelos
Chamilpa, Morelos.
Mexico

email:    [email-masked]