From chemistry-request@server.ccl.net Sun Dec 9 09:39:04 2001 Received: from 263.net ([202.96.44.48]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id fB9Ec3i26736 for ; Sun, 9 Dec 2001 09:39:04 -0500 Received: by 263.net (Postfix, from userid 60001) id 274AC1C95944B; Sun, 9 Dec 2001 22:34:48 +0800 (CST) MIME-Version: 1.0 Message-Id: <3C137688.18028@mta6> Content-Type: Multipart/Alternative; boundary="Boundary-=_AZdEomLqZXzuJnLwoLUyJyZgnDxM" Date: Sun, 9 Dec 2001 22:34:48 +0800 (CST) From: "蛎市" To: chemistry@ccl.net Subject: =?gb2312?B?TVAyIGVuZXJneSB3aXRoIERGVCBnZW9tZXRyeQ==?= X-Priority: 3 X-Originating-IP: [218.2.137.253] X-Mailer: Coremail2.0 Copyright Tebie Ltd., 2001 --Boundary-=_AZdEomLqZXzuJnLwoLUyJyZgnDxM Content-Type: Text/Html; charset="gb2312" Content-Transfer-Encoding: 8bit Dear Sir:

I am using Gaussian98 to study a chemical reaction.I don't know if it is right to use DFT geometry to do singlepoint calculation with MP2 method in TS and minimum.
The system that I am handle is a week interaction system.the energy of DFT is not
as good as the one of MP2.

thank you
chenhui
Dept chemistry Nanjing university
P R China

--Boundary-=_AZdEomLqZXzuJnLwoLUyJyZgnDxM Content-Type: Text/Plain; charset="gb2312" Content-Transfer-Encoding: 8bit Dear Sir: I am using Gaussian98 to study a chemical reaction.I don't know if it is right to use DFT geometry to do singlepoint calculation with MP2 method in TS and minimum. The system that I am handle is a week interaction system.the energy of DFT is not as good as the one of MP2. thank you chenhui Dept chemistry Nanjing university P R China --Boundary-=_AZdEomLqZXzuJnLwoLUyJyZgnDxM-- From chemistry-request@server.ccl.net Sun Dec 9 12:02:34 2001 Received: from epyon.INS.cwru.edu (root@[129.22.9.21]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id fB9H2Yi31236 for ; Sun, 9 Dec 2001 12:02:34 -0500 Received: from gavin (chem51286.CHEM.CWRU.Edu [129.22.129.217]) by epyon.INS.cwru.edu with SMTP (8.11.6+cwru/CWRU-3.8) id fB9H2Ld19469; Sun, 9 Dec 2001 12:02:21 -0500 (EST) (from hxt10@po.cwru.edu for ) Message-ID: <001501c180d3$ff0113c0$d9811681@cwru.edu> Reply-To: "Hui-Hsu $Gavin$ Tsai" From: "Hui-Hsu $Gavin$ Tsai" To: Subject: Molecular Orbital Analysis Date: Sun, 9 Dec 2001 12:07:34 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0012_01C180AA.16097A00" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2479.0006 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2479.0006 This is a multi-part message in MIME format. ------=_NextPart_000_0012_01C180AA.16097A00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi, I have a MO analysis question to ask for your help. In the chemistry point of view, chemists always want to express the = bonding or antibonding from simple concepts such as pi bonding, and/or = coordinated bonding. But the question is how to express these concepts = > from the MO calculations? For example, we have one coordinated bonding = (e.g. Nickel-Pyrrole). Of course, we can visualize the MO, but the MO is = the final results of the mixing of different atomic orbitals. How can we = determinate the MO is the coordinated bonding? How can we determinate = the molecular orbital is the bonding between d orbitals (in metal) and = the lone pair (in the pyrrole ring)? Is there any simple anslysis which = can decompose the MO into atomic orbitals or somple chemical concepts? = Thanks. Any comment is welcomed. Gavin=20 ------=_NextPart_000_0012_01C180AA.16097A00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Hi,

I have a MO analysis = question to ask=20 for your help.

In the chemistry point of view, = chemists always=20 want to express the bonding or antibonding from simple concepts = such as pi=20 bonding, and/or coordinated bonding. But the question is how to = express=20 these concepts from the MO calculations? For=20 example, we have one coordinated bonding (e.g. Nickel-Pyrrole). Of = course, we=20 can visualize the MO, but the MO is the final results of the mixing of = different=20 atomic orbitals. How can we determinate the MO is the coordinated = bonding? How=20 can we determinate the molecular orbital is the bonding between d = orbitals (in=20 metal) and the lone pair (in the pyrrole ring)? Is there any simple = anslysis=20 which can decompose the MO into atomic orbitals or somple chemical=20 concepts? Thanks.

Any comment is welcomed.

Gavin

------=_NextPart_000_0012_01C180AA.16097A00-- From chemistry-request@server.ccl.net Sun Dec 9 12:43:49 2001 Received: from cns.FTA-Berlin.de ([141.16.244.4]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id fB9Hhmi00858 for ; Sun, 9 Dec 2001 12:43:48 -0500 Received: from langmuir.aca-berlin.de (langmuir.ACA-Berlin.de [141.16.16.120]) by cns.FTA-Berlin.de (8.11.3/8.11.3/SuSE Linux 8.11.1-0.5) with ESMTP id fB9Hglv08676; Sun, 9 Dec 2001 18:42:47 +0100 Date: Sun, 9 Dec 2001 18:41:59 +0100 (CET) From: To: =?X-UNKNOWN?B?s8K71A==?= cc: Subject: Re: CCL:=?gb2312?B?TVAyIGVuZXJneSB3aXRoIERGVCBnZW9tZXRyeQ==?= In-Reply-To: <3C137688.18028@mta6> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi, DFT for weak interactions is dangerous, because it shows the_wrong_ behaviour for r goes infinity in comparison to HF (and the impossible analytic solution). Additionally MP2 is considered as (correlation) energy correction to HF. Since you don't know in DFT, how much correlation you get, I think this combination does not make sense. Alex --- Dr. Alexander Hofmann Institute for Applied Chemistry Berlin-Adlershof P.O. Box 96 11 56 Richard-Willstaetter-Str. 12 D-12474 Berlin D-12489 Berlin hofmann@aca-berlin.de Tel.: +49-30-6392-4408 Fax.: +49-30-6392-4350 http://www.aca-berlin.de From chemistry-request@server.ccl.net Sun Dec 9 18:52:03 2001 Received: from sungod.ccs.yorku.ca ([130.63.236.104]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id fB9Nq2i13552 for ; Sun, 9 Dec 2001 18:52:02 -0500 Received: from sunlight.ccs.yorku.ca (sunlight.ccs.yorku.ca [130.63.236.85]) by sungod.ccs.yorku.ca (8.9.3/8.9.3) with ESMTP id SAA10626; Sun, 9 Dec 2001 18:51:48 -0500 (EST) Received: from localhost (serge@localhost) by sunlight.ccs.yorku.ca (8.9.3/8.9.3) with ESMTP id SAA04285; Sun, 9 Dec 2001 18:51:47 -0500 (EST) X-Authentication-Warning: sunlight.ccs.yorku.ca: serge owned process doing -bs Date: Sun, 9 Dec 2001 18:51:47 -0500 (EST) From: Serge Gorelsky X-X-Sender: To: "Hui-Hsu (Gavin) Tsai" cc: Subject: Re: CCL:Molecular Orbital Analysis In-Reply-To: <001501c180d3$ff0113c0$d9811681@cwru.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII You can find answers to your questions in the folowing papers: Dapprich, S.; Frenking, G. J. Phys. Chem. 1995, 99, 9352. Pidun, U.; Frenking, G. J.Organomet.Chem. 1996, 525, 269. Frenking, G.; Pidun, U. J. Chem. Soc., Dalton Trans. 1997, 1653. Frenking, G. J. Organomet. Chem. 2001, 635, 9. and Gorelsky, S. I.; Lever, A. B. P. J.Organomet.Chem. 2001, 635, 187. Serge > I have a MO analysis question to ask for your help. > > In the chemistry point of view, chemists always want to express the bonding > or antibonding from simple concepts such as pi bonding, and/or > coordinated bonding. But the question is how to express these concepts > from the MO calculations? For example, we have one coordinated bonding > (e.g. Nickel-Pyrrole). Of course, we can visualize the MO, but the MO is > the final results of the mixing of different atomic orbitals. How can we > determinate the MO is the coordinated bonding? How can we determinate > the molecular orbital is the bonding between d orbitals (in metal) and > the lone pair (in the pyrrole ring)? > Is there any simple anslysis which > can decompose the MO into atomic orbitals or somple chemical concepts? yes, there is. Check Gorelsky, S. I.; Lever, A. B. P. J.Organomet.Chem. 2001, 635, 187. and http://www.chem.yorku.ca/grad/SG/AOMix/ ________________________________________________________________ S. I. Gorelsky Department of Chemistry, York University 4700 Keele Street, Toronto, Ontario M3J 1P3 Canada Phone: 416-736-2100 ext#70131 Fax: 416-736-5936 http://www.chem.yorku.ca/grad/SG/ ________________________________________________________________