From owner-chemistry ^%at%^ ccl.net Mon Mar  5 19:54:00 2012
From: "James Mao xjamesmao*|*gmail.com" <owner-chemistry(0)server.ccl.net>
To: CCL
Subject: CCL: Entropy calculations for condensed state
Message-Id: <-46425-120305195228-17067-MusxCT+M0EJY1lqAFhqaWA(0)server.ccl.net>
X-Original-From: "James  Mao" <xjamesmao=gmail.com>
Date: Mon, 5 Mar 2012 19:52:16 -0500


Sent to CCL by: "James  Mao" [xjamesmao|a|gmail.com]
Dear cclers,

I am trying to evaluate the entropy change of a reaction (1,3-cyclohexadiene -> 1,4-cyclohexadiene). They both are liquid and the experimental data shows the entropy change is negative, which is reasonable since 1,4-cyclohexadiene has a higher symmetry.

However calculations for gas phase all show 1,3-cyclohexadiene has a lower entropy than 1,4-cyclohexadiene (I tried different basis sets and methods). Is this due to the reason that symmetry factor is not included for a single molecule calculation in gas state? The arrangements of the molecules in liquid phase should contribute a large part of entropy, right? As to my problem, is there any way to evaluate entropy in liquid phase?

Any suggestion will be greatly appreciated.

Best,
James