Re: CCL:BSSE



Hi Olegas,
 > In the "standard" BSSE equation (for a dimer AB):
 >
 > BSSE(AB) =3D E(AB)^AB - E(A)^A - E(B)^B + [E(A')^A - E(A')^AB + E(B)^B - =
 > E(B)^AB]
 >
 > I've got most of the parameters, but how in G98W do I calculate E(A)^AB =
 > and E(B)^AB, i.e. the energy of the monomer units in terms of the dimer =
 > basis set.
 With Gaussian, the keyword Massage has to be used for counterpoise
 corrections (assuming it's the same for G98 and G98W).  Have a look at the
 Gaussian manual: http://www.gaussian.com/00000452.htm.
 There is an example there as well. However, don't believe the sentence
 about counterpoise being only a crude estimate, have a look at the
 following papers to learn more about BSSE and Counterpoise:
 -  F.B. van Duijneveldt, J.G.C.M. van Duijneveldt-van de Rijdt, and
    J.H. van Lenthe, Chem. Rev. 94, 1873, 1994 (on counterpoise theory)
 -  S. Simon, M. Duran, J.J. Dannenberg, J. Chem. Phys. 105, 1996
    (on geometry optimizations on BSSE-corrected potential energy surfaces).
 -  F.B. van Duijneveldt, "Basis Superposition Error"
    in "Molecular Interactions" S. Scheiner (ed.), Wiley (1997)
 -  T. van Mourik, A.K. Wilson, K.A. Peterson, D.E. Woon, T.H. Dunning, Jr.,
    Adv. Quant. Chem. 31, 105, 1999 (showing BSSE effects on interaction
    energies, distances, and frequencies).
 HTH,
 Tanja
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      Tanja van Mourik
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      Chemistry Department
      University College London    phone:    +44 (0)20-7679-4663
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