From owner-chemistry@ccl.net Sun Aug 6 14:53:00 2017 From: "Jens Spanget-Larsen spanget*|*ruc.dk" To: CCL Subject: CCL:G: Counterpoise correction Message-Id: <-52920-170806145151-14541-1zJwHrDtGBw8XnpHZaZvgQ*_*server.ccl.net> X-Original-From: Jens Spanget-Larsen Content-Language: da-DK Content-Type: multipart/alternative; boundary="_000_A94E15A372E6194CA8719D62642F67448BB24350MBX1adrucdk_" Date: Sun, 6 Aug 2017 18:51:43 +0000 MIME-Version: 1.0 Sent to CCL by: Jens Spanget-Larsen [spanget]^[ruc.dk] --_000_A94E15A372E6194CA8719D62642F67448BB24350MBX1adrucdk_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear CCL: I am interesting in determining the energy of the reaction monomer + monomer =3D dimer. The reaction energy E(reaction) would be equal to the binding energy or the= stabilization energy of the dimer. Performing a counterpoint corrected geo= metry optimization of the dimer with Gaussian, you obtain energy data like: Counterpoise corrected energy =3D -649.051460350315 BSSE energy =3D 0.001326284020 sum of monomers =3D -649.042576742109 complexation energy =3D -6.41 kcal/mole (raw) complexation energy =3D -5.57 kcal/mole (corrected) Please explain what these energies mean; in particular, what are the two co= mplexation energies? The 'sum of monomers' must refer to monomer geometries in the more or less = distorted geometry adapted to the dimer formation. If I want the energy of = the abovementioned reaction, is it correct to form the difference E(reaction) =3D E(dimer) - 2 * E(monomer) where E(dimer) is the counterpoise corrected energy as given above, and E(m= onomer) is the energy of the free, undistorted monomer? Yours, Jens >--< ------------------------------------------------------ JENS SPANGET-LARSEN Office: +45 4674 2710 Dept. of Science Fax: +45 4674 3011 Roskilde University Mobile: +45 2320 6246 P.O.Box 260 E-Mail: spanget__ruc.dk DK-4000 Roskilde, Denmark Web: thiele.ruc.dk/~spanget ------------------------------------------------------ --_000_A94E15A372E6194CA8719D62642F67448BB24350MBX1adrucdk_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Dear CCL:

I am interesting in determining the energy of the reaction

monomer + monomer =3D dimer.

The reaction energy E(reaction) would be equal to the binding energy or = the stabilization energy of the dimer. Performing a counterpoint corrected = geometry optimization of the dimer with Gaussian, you obtain energy data li= ke:

Counterpoise corrected energy =3D    -649.051460350= 315
            &nb= sp;      BSSE energy =3D    &n= bsp; 0.001326284020
            &nb= sp; sum of monomers =3D    -649.042576742109
           complexation e= nergy =3D      -6.41 kcal/mole (raw)
           complexation e= nergy =3D      -5.57 kcal/mole (corrected)

Please explain what these energies mean; in particular, what are the two= complexation energies?

The 'sum of monomers' must refer to monomer geometries in the more or le= ss distorted geometry adapted to the dimer formation. If I want the energy = of the abovementioned reaction, is it correct to form the difference

E(reaction) =3D E(dimer) - 2 * E(monomer)

where E(dimer) is the counterpoise corrected energy as given above, and = E(monomer) is the energy of the free, undistorted monomer?

Yours, Jens >--<

&nb= sp; = &nb= sp; = &nb= sp;

--= ----------------------------------------------------

JENS SPANGET-LARSEN &= nbsp; Office: +45= 4674 2710

Dept. of Science &nbs= p; Fax: &n= bsp; +45 4674 3011

Roskilde University &= nbsp; Mobile: +45= 2320 6246

P.O.Box 260 &nb= sp; E-Mail:&nbs= p; spanget__ruc.dk=

DK-4000 Roskilde, Denmark W= eb: thiele.ruc.dk/~spanget

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