Subject: counterpoise correction

From: Adel El-Azhary <[email-masked]>
Date: Fri, 01 Jun 2001 17:38:03 +0300

Dear Netters:

I am doing calculations on metal cation complexes using the gaussian
program but not sure how to calculated the counterpoise correction. So
any help is most appreciated. I am trying to do it first say for
Mg2+(H2O). I know that the first two calculations need to be done for
Mg2+(H2O) at its optimized geometry, in the first we zero out the charge
on the metal cation and in the second we zero out the nuclear charge on
water but I problem I am not sure about what is the third calculation
which need to be done and how to calculated the counterpoise correction
> from these three calculations. To make things clearer I included the
data for these two calculations.

Thank you very much in advance for the assistance.

Best regards,

Adel El-Azhary

=========================================================

 #p HF/6-31+g*  massage test

 H2O   HF   Mg2+

 2 1
 Mg   0.0  0.0        0.933354
 o2    0.0  0.0       -1.003294
 h3    0.0  0.770810  -1.586945
 h4    0.0 -0.770810  -1.586945

 1 nuc 0.0

 --link1--

 #p HF/6-31+g*  massage test

 HF   Mg2+

 2 1
 Mg   0.0  0.0        0.933354
 o2   0.0  0.0       -1.003294
 h3   0.0  0.770810  -1.586945
 h4   0.0 -0.770810  -1.586945

 2 nuc 0.0
 3 nuc 0.0
 4 nuc 0.0

======================================================