From chemistry-request@server.ccl.net Thu Jun 13 16:57:53 2002
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Message-ID: <001d01c2131f$ae132780$4bd8f143@anick000>
From: "David J Anick" <David.Anick@gte.net>
To: chemistry@ccl.net
Subject: Thermal corrections
Date: Thu, 13 Jun 2002 14:17:08 -0700


Dear CCLers,

Having completed a Gaussian98 frequencies/ZPE calculation
at an optimized geometry, I now find that I would like to know
the thermal corrections to energy, enthalpy and Gibbs free
energy at a different temperature (77 K) than the one that
Gaussian98 automatically calculated (298 K).

I don't want to re-run the calculation if possible because
it took nearly a week.

Can anyone tell me the formula(s) that Gaussian98 uses
to compute these data?  If it involves integrating Cp or
Cp/T, how do I obtain Cp as a function of temperature?

Thank you in advance,

David Anick MD PhD
David.Anick@gte.net