Subject: MP2 energy with DFT geometry

From: "�»�" <[email-masked]>
Date: Sun, 9 Dec 2001 22:34:48 +0800 (CST)

Dear Sir:
  
I am using Gaussian98 to study a chemical reaction.I don't know if it is right to use DFT geometry to do singlepoint calculation with MP2 method in TS and minimum.
The system that I am handle is a week interaction system.the energy of DFT is not 
as good as the one of MP2.

thank you
chenhui
Dept chemistry Nanjing university 
P R China

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From: <[email-masked]>
Date: Sun, 9 Dec 2001 18:41:59 +0100 (CET)

Hi,

DFT for weak interactions is dangerous, because it shows the_wrong_
behaviour for r goes infinity in comparison to HF (and the impossible
analytic solution).

Additionally MP2 is considered as (correlation) energy correction to HF.
Since you don't know in DFT, how much correlation you get, I think this
combination does not make sense.

Alex

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Dr. Alexander Hofmann
Institute for Applied Chemistry Berlin-Adlershof
P.O. Box 96 11 56       Richard-Willstaetter-Str. 12

D-12474 Berlin          D-12489 Berlin

[email-masked]

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http://www.aca-berlin.de