Re: CCL:counterpoise correction

 Hi,
 The trick with counterpoise correction is to use the result from the
 original non-massaged calculation using all the atoms and then subtract
 the interaction energies obtained with the two massaged calculations with
 the interactions to the empty basis functions.
 :-)
 /harald
 Harald Svedung (Ph.Lic.)      phone:  +46-31-7722816
 Department of Chemistry       fax:  +46-31-167194
 Physical Chemistry            home phone:+46-31-240897, +46-709223206
 Goeteborg University          home e-mail: harald.svedung;at;svedung.pp.se
 SE-412 96 Goeteborg, Sweden.  www.che.chalmers.se/~svedung/welcome.html
 On Fri, 1 Jun 2001, Adel El-Azhary wrote:
 > 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
 >
 > ======================================================
 >
 >
 >
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