Subject: CCL: dissociation problem

From: Pierre Archirel <pierre.archirel !! lcp.u-psud.fr>
Date: Fri, 08 Jul 2005 11:11:09 +0200

Dear Elmar,
I would say the issue you are refering to has nothing to do with PCM,
but is probably due to a DFT artifact, which is the wrong dissociation
of NaCl, even in the gas phase. Your asymptotic system is a singlet open 
shell,
with two electrons, alone in their orbitals. DFT poorly addresses this 
situation,
because of the approximative cancelation of the self interaction.
To check this:
1- verify that at the crude HF level, your long range PCM energy is the sum
of the PCM energies of the fragments.
2-  check if your (gas phase) long range B3LYP calculation yields
fragments with 0 charges. If not, DFT is of no help to you.
P.

__________________________________________________________

 Pierre Archirel
 Groupe de Chimie Thiorique
 Laboratoire de Chimie Physique      Tel: 01 69 15 63 86
 Bat 349                             Fax: 01 69 15 61 88
 91405 Orsay Cedex
 France                   pierre.archirel !! lcp.u-psud.fr
__________________________________________________________