From chemistry-request@ccl.net Sun Jun  8 01:42:20 2003
Received: from sungoddess.ccs.yorku.ca (mailrelay.yorku.ca [130.63.236.144])
	by server.ccl.net (8.12.8/8.12.8) with ESMTP id h585gKkr018637
	for <chemistry*at*ccl.net>; Sun, 8 Jun 2003 01:42:20 -0400
Received: from curl.gkcl.yorku.ca (curl.gkcl.yorku.ca [130.63.232.224])
	by sungoddess.ccs.yorku.ca (8.12.9/8.12.8) with ESMTP id h585gJ0O022793
	for <chemistry*at*ccl.net>; Sun, 8 Jun 2003 01:42:19 -0400 (EDT)
Received: (from chan@localhost)
	by curl.gkcl.yorku.ca (8.10.0/8.10.0) id h585gIL04695
	for chemistry*at*ccl.net; Sun, 8 Jun 2003 01:42:18 -0400 (EDT)
From: Wai-To Chan <chan*at*curl.gkcl.yorku.ca>
Message-Id: <200306080542.h585gIL04695*at*curl.gkcl.yorku.ca>
Subject: On basis sets for calculating thermochemistry properties
To: chemistry*at*ccl.net
Date: Sun, 8 Jun 2003 01:42:18 -0400 (EDT)
X-Mailer: ELM [version 2.5 PL3]
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Dear all,

I am calculating thermochemistry properties by Gaussian DFT method. Can 
anyone give me some suggestions on basis sets for the calculation? 
Which is the minimum basis set I can use in this calculation is 
reasonable? With small basis sets (sto-3g, 3-21g), which one can get 
better results for thermochemistry properties by Gaussian DFT method?

Thanks to you all,

Holly
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

I used the xalpha/3-21g method for geometry optimization
of LARGE molecules in the past and got some decent results. But 
sto-3g and 3-21g won't be a good choice for reliable thermochemistry 
calculation with Hybrid DFT method like B3LYP. Use a basis set at least 
as large as 6-31+G(d)/6-31+G(d,p). The inclusion of '+' can make a difference. 
You may refer to 

   J. Phys. Chem. A, (2003) vol 107 pg 1384-1388 by Lynch, Zhao and Truhlar

for an assessment of the accuracy of the MPW1PW91/6-31+G(d,p) method. 

Wai-To Chan


From chemistry-request@ccl.net Sun Jun  8 16:00:57 2003
Received: from telebit.ru (mail.knet.ru [217.107.81.59])
	by server.ccl.net (8.12.8/8.12.8) with ESMTP id h58K0ukr014819
	for <chemistry*at*ccl.net>; Sun, 8 Jun 2003 16:00:57 -0400
Received: from 81.25.172.92 ([81.25.172.92] verified)
  by telebit.ru (CommuniGate Pro SMTP 4.0.6)
  with ESMTP id 781326 for chemistry*at*ccl.net; Sun, 08 Jun 2003 23:59:57 +0400
Date: Sun, 8 Jun 2003 23:59:06 +0400
From: Gregory Shamov <gas5x*at*bancorp.ru>
X-Mailer: The Bat! (v1.61) Personal
Reply-To: Gregory Shamov <gas5x*at*bancorp.ru>
Organization: KSU
X-Priority: 3 (Normal)
Message-ID: <17210745488.20030608235906*at*bancorp.ru>
To: chemistry*at*ccl.net
Subject: CCL: barrier of the radical reaction involving transition metall?
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Hello All,

I have to estimate barrier of the following reaction:

  [Pt] + R-X --> [Pt].-X + R.

Where [Pt] is square-planar platinum(II) complex.

I have tryed to do PES scan with mixing guess UHF, but there are hard
convergence problems.

Is it possible to calculate it with quantum-chemical methods?

If yes, could someone advice me how to do it, what is the best suitable
QM method, etc. Or may be there are publications where similar work
has been done?

Any suggestions will be appericated.

-- 
Best regards,
 Gregory Shamov,
 Kazan State University                         mailto:gas5x*at*bancorp.ru