From chemistry-request;at;ccl.net Thu May 19 09:02:46 2005
Received: from server.ccl.net (ccl [127.0.0.1])
	by server.ccl.net (8.13.1/8.13.1) with ESMTP id j4JD2jUu015477
	for <chemistry () ccl.net>; Thu, 19 May 2005 09:02:45 -0400
Received: (from apache.,at,.localhost)
	by server.ccl.net (8.13.1/8.13.1/Submit) id j4JD2jcZ015476
	for chemistry () ccl.net; Thu, 19 May 2005 09:02:45 -0400
Date: Thu, 19 May 2005 09:02:45 -0400
Message-Id: <200505191302.j4JD2jcZ015476 () server.ccl.net>
X-Authentication-Warning: server.ccl.net: apache set sender to chemistry-request () ccl.net using -f
From: "Rich, , Talbot" <rtalbot () cambridgesoft.com>
To: chemistry () ccl.net
X-Web-Message-Number: 050519090220-15449
Subject: W:ideal gas heat capacity
X-Spam-Status: No, score=-2.8 required=5.0 tests=ALL_TRUSTED autolearn=failed 
	version=3.0.3
X-Spam-Checker-Version: SpamAssassin 3.0.3 (2005-04-27) on server.ccl.net

"I have been using Chem3D to calculate vibrational frequencies using MOPAC (FORCE THERMO PRECISE) and a PM3 method.  The printout gives heat capacity which looks like Cp for propane and Cv for 1,1,1-trifluoropropane.  Is there an extra correction that needs to be made when calculating the ideal gas heat capacity of fluorine containing molecules from the vibrational frequencies?"

One of our users asked this question, but I am having difficulty in finding him a solution.  I thought I would check with the experts on this list for any insights.

Thanks,

Rich Talbot
rtalbot () cambridgesoft.com