Subject: virtual orbitals and DFT

From: "Domingo Mariano A. Vera" <[email-masked]>
Date: Tue, 27 Jul 1999 11:36:47 -0500

Hi Folks

	I have a little question that I previously asked in a post grade course
and in a bar but I never got a definitive answer. 
	How much reliable are (or how much sense they have) the virtual
orbitals from a DFT calculation? More specifically, consider non local,
state of the art, mixed formalisms (using the hf density) such as blyp,
b3lyp or PDB (with standar all electron basis), for example. I noted
that for critical systems (open shell, net charge, high correlation
effects) such as some radical anions, at least the LUMO up to LUMO+2
have the same energy pattern and the coefficients are very similar to
MP2. 

Best regards
Mariano.
	
-- 
D. Mariano A. Vera
INFIQC / Departamento de Quimica Organica
Facultad de Ciencias Quimicas - Universidad Nacional de Cordoba.
Ciudad Universitaria - 5000 Cordoba - ARGENTINA.
Voice: 54-351-4334170
Fax:   54-351-4333030
[email-masked]