From owner-chemistry@ccl.net Fri Dec  8 01:44:00 2006
From: "Ulrike Salzner salzner%x%fen.bilkent.edu.tr" <owner-chemistry^-^server.ccl.net>
To: CCL
Subject: CCL: Calculation of band gap of conducting polymer
Message-Id: <-33223-061208011826-17171-ofJpuvyGrxbJnMT9VgMt2A^-^server.ccl.net>
X-Original-From: Ulrike Salzner <salzner|*|fen.bilkent.edu.tr>
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Date: Fri, 08 Dec 2006 08:18:21 +0200
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Sent to CCL by: Ulrike Salzner [salzner],[fen.bilkent.edu.tr]
Dear Jun,
You got already good information regarding your question. I would like
to add a few comments, however. Most of these methods will give you gas
phase data for the maximum absorption. A CV measures the onset of
absorption in condensed phases. 

Maximum absorption and onset of absorption in optical spectra differ by
around 0.5 eV, depending on the system. (e.g. PA: 1.9 vs. 1.4 eV, PT:
2.7 vs 2.0 eV and so on)

Onset of absorption in UV spectra and electrochemical band gaps usually
coincide, but they do not have to. 

Medium (solvent effects are known for polyenes for instance and are
about 0.3-0.4 eV (see dAmico, JACS, 1980, 102, 1777).


In the solid state you will have to consider Davydov splitting of the
bands (see Muccini et al. J. Chem. Phys. 1998, 109, 10513).

Thus even with a very accurate method, you will not and you should not
reproduce the electrochemical band gap. 

Best regards,
Ulrike 

On Thu, 2006-12-07 at 11:03 -0500, Jun Deng jdeng!A!ppg.com wrote:
> Sent to CCL by: "Jun  Deng" [jdeng++ppg.com]
> Dear ccler:
> 
> Will you be able to give some advice on how to calculate the band gap of conducting polymers, which can be compared with the experimental result measured from CV?  I found some references using DFT to do this, but the correlations with experimental results are rather poor.
> 
> Regards,
> 
> Jun Deng> 
> 
> 
>


From owner-chemistry@ccl.net Fri Dec  8 16:06:00 2006
From: "Jim Kress ccl_nospam_-_kressworks.com" <owner-chemistry||server.ccl.net>
To: CCL
Subject: CCL: Battery Simulation
Message-Id: <-33224-061208160443-9327-U3OVRQEVOm6LgWdziZj/KA||server.ccl.net>
X-Original-From: "Jim  Kress" <ccl_nospam . kressworks.com>
Date: Fri, 8 Dec 2006 16:04:43 -0500


Sent to CCL by: "Jim  Kress" [ccl_nospam()kressworks.com]
 Anybody on the list know of any atomic/molecular level battery simulation tools (academic or commercial)?

Any helpful replies would be appreciated.

Jim


From owner-chemistry@ccl.net Fri Dec  8 23:20:01 2006
From: "Anonymous Anonymous mail231188*_*10minutemail.com" <owner-chemistry:+:server.ccl.net>
To: CCL
Subject: CCL: metadynamics (kind of adaptive biased MD) in AMBER/SANDER
Message-Id: <-33225-061208223448-24877-+ybpW+XdPKBbkNKIEMN4BA:+:server.ccl.net>
X-Original-From: "Anonymous  Anonymous" <mail231188###10minutemail.com>
Date: Fri, 8 Dec 2006 22:34:48 -0500


Sent to CCL by: "Anonymous  Anonymous" [mail231188 a 10minutemail.com]
http://planck.physics.ncsu.edu/metasander/