From owner-chemistry@ccl.net Fri Aug 8 22:45:00 2008 From: "Lorena Romero lorena.webmaster---gmail.com" To: CCL Subject: CCL:G: thermodynamic calculations Message-Id: <-37526-080808224145-31140-SeJ9tFt3NUkDlIwi70iy1Q|*|server.ccl.net> X-Original-From: "Lorena Romero" Content-Type: multipart/alternative; boundary="----=_Part_59894_30768967.1218245959666" Date: Fri, 8 Aug 2008 21:39:19 -0400 MIME-Version: 1.0 Sent to CCL by: "Lorena Romero" [lorena.webmaster:+:gmail.com] ------=_Part_59894_30768967.1218245959666 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline You can read the file "Thermo" in Gaussian webpage as an introduction, and then looking at szabo=B4s reference book cited there. But, being more specific DG =3D DH - TDS ; DS =3D (DH - DG) / T Where DX =3D Xtransition state - Xreactant. T =3D temperature (Kelvin) You got the enthalpy and the free energy from the output file. Be careful with the units, (hartrees). 2008/8/8 Hamdy Saad El Sheshtawy h.elsheshtawy~~jacobs-university.de < owner-chemistry]|[ccl.net> > > Sent to CCL by: "Hamdy Saad El Sheshtawy" [h.elsheshtawy ~ > jacobs-university.de] > Dear all, > I am doing some calculations on the transition state optemizations and I > want to calculate the entropy from the thermodynamics outputs. can any on= e > tell me how to calculate the entropy the enthalby and the free energy. > best > Hamdy > > > > -=3D This is automatically added to each message by the mailing script = =3D-> > > --=20 "La alegr=EDa est=E1 en la lucha, en el esfuerzo, en el sufrimiento que sup= one la lucha y no en la victoria." Mahatma Gandhi ------=_Part_59894_30768967.1218245959666 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline
You can read the file "Thermo" in Gaussian webpa= ge as an introduction, and then looking at szabo=B4s reference book cited t= here.

But, being more specific DG =3D DH - TDS ; DS =3D = (DH - DG) / T

Where DX =3D Xtransition state - Xreactant.
<= br>
T =3D temperature (Kelvin)

You got the= enthalpy and the free energy from the output file.

Be careful with the units, (hartrees).


<= div>
2008/8/8 Hamdy Saad El Sheshtawy h.elsheshta= wy~~jacobs-university.de <owner-chemistry]|[= ccl.net>

Sent to CCL by: "Hamdy Saad El Sheshtawy" [h.elsheshtawy ~ jacobs-university.de]
Dear all,
I am doing some calculations on the transition state optemizations and I wa= nt to calculate the entropy from the thermodynamics outputs. can any one te= ll me how to calculate the entropy the enthalby and the free energy.
best
Hamdy



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--
"La alegr=EDa est= =E1 en la lucha, en el esfuerzo, en el sufrimiento que supone la lucha y no= en la victoria."=09
Mahatma Gandhi
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