From chemistry-request@ccl.net Fri Sep 24 15:00:08 2004 Received: from mxout3.cac.washington.edu (mxout3.cac.washington.edu [140.142.32.166]) by server.ccl.net (8.12.8/8.12.8) with ESMTP id i8OK07io007597 for ; Fri, 24 Sep 2004 15:00:07 -0500 Received: from hymn14.u.washington.edu (hymn14.u.washington.edu [140.142.16.151]) by mxout3.cac.washington.edu (8.13.1+UW04.08/8.13.1+UW04.08) with ESMTP id i8OKAfDD005517 for ; Fri, 24 Sep 2004 13:10:41 -0700 Received: from localhost (localhost [127.0.0.1]) by hymn14.u.washington.edu (8.13.1+UW04.08/8.13.1+UW04.08) with ESMTP id i8OKAee3009761 for ; Fri, 24 Sep 2004 13:10:40 -0700 Received: from [140.142.15.144] by hymn14.u.washington.edu via HTTP; Fri, 24 Sep 2004 13:10:40 PDT Date: Fri, 24 Sep 2004 13:10:40 -0700 (PDT) From: liaoyi_at_u.washington.edu To: chemistry_at_ccl.net Subject: parameters for conjuagation. Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed X-Spam-Status: No, hits=2.2 required=7.5 tests=DEAR_SOMETHING,NO_REAL_NAME autolearn=no version=2.61 X-Spam-Checker-Version: SpamAssassin 2.61 (1.212.2.1-2003-12-09-exp) on servernd.ccl.net Dear Sirs: I have general question for you. When we talk about conjugated systems, we can have some general sense about which molecule has better conjugation. For example, a planar structure is better than a twisted one, double bond is better than triple bond, etc. I wonder if there are some sort of parameters that can be used to at least qualitively characterize the conjugation or how easy electron density flows through a bridge. Thanks. Yi From chemistry-request@ccl.net Sat Sep 25 02:23:28 2004 Received: from turmiel.ch.uj.edu.pl (turmiel.ch.uj.edu.pl [149.156.71.252]) by server.ccl.net (8.12.8/8.12.8) with ESMTP id i8P7NQoU008585 for ; Sat, 25 Sep 2004 02:23:27 -0500 Received: from turmiel.ch.uj.edu.pl (localhost.localdomain [127.0.0.1]) by turmiel.ch.uj.edu.pl (8.12.8/8.12.8) with ESMTP id i8P7Y1lC011976 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO) for ; Sat, 25 Sep 2004 09:34:02 +0200 From: makowskm_at_chemia.uj.edu.pl Received: (from apache@localhost) by turmiel.ch.uj.edu.pl (8.12.8/8.12.8/Submit) id i8P7Xxs3011974; Sat, 25 Sep 2004 09:33:59 +0200 X-Authentication-Warning: turmiel.ch.uj.edu.pl: apache set sender to makowskm_at_chemia.uj.edu.pl using -f Received: from 83.29.94.67 (SquirrelMail authenticated user makowskm) by mail.ch.uj.edu.pl with HTTP; Sat, 25 Sep 2004 09:33:59 +0200 (CEST) Message-ID: <1309.83.29.94.67.1096097639.squirrel_at_mail.ch.uj.edu.pl> Date: Sat, 25 Sep 2004 09:33:59 +0200 (CEST) Subject: Re: CCL:configuration interaction To: X-Priority: 3 Importance: Normal X-Mailer: SquirrelMail (version 1.2.11) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Content-Transfer-Encoding: 8bit X-Virus-Scanned: by amavisd-new X-Spam-Status: No, hits=1.0 required=7.5 tests=NO_REAL_NAME autolearn=no version=2.61 X-Spam-Checker-Version: SpamAssassin 2.61 (1.212.2.1-2003-12-09-exp) on servernd.ccl.net You should use something like CIS(D,NStates=x,root=y) to obtain perturbational second order correction to CIS energy of y-th state. But you must remember that CIS even with second order correction is quite rarely well suited to obtain reliable results for excited states, except maybe the state dominated by HOMO->LUMO single excitation. When you are interested in quantitative information about excited states you may think of using CASSCF/CASPT2 metodology or some version of coupled cluster methods (STOEM-CC or SAC-CI) or TD DFT. Yours, Dr Marcin Makowski Jagiellonian University Faculty of Chemistry > Dear Netters, > > I try to study excited states of an organic molecule using G98. > I would like to find the energy of the four lower excited states. I > use CI. > > I did CIS and get the information I wanted but with wrong values for > the energy of the excited states. so I would like to include double > substitutions in the calculation. I use the keyword CISD : I get the > total energy corrected by the CI but I could not get the energy of the > excited states. Is it possible to have this information with G98? Any > advice for another code? > > thanks, bye, > C. > > > --------------------------------- > Criez gratuitement votre Yahoo! Mail avec 100 Mo de stockage ! > Criez votre Yahoo! Mail > > Le nouveau Yahoo! Messenger est arrivi ! Dicouvrez toutes les > nouveautis pour dialoguer instantaniment avec vos amis.Tilichargez > GRATUITEMENT ici !