Return-Path: Message-ID: <1664.149.156.71.133.1058335962.squirrel_at_mail.ch.uj.edu.pl> Date: Wed, 16 Jul 2003 08:12:42 +0200 (CEST) Subject: degenerate representations and quantum packages From: To: chemistry_at_ccl.net As far as I know symmetry groups with degenerate representations are not treated exactly by any standard quantum chemiacla package. Instead they work in the largest abelian subgroup which will be in your case D2. That is why you may obtain symmetry-broken state. Yours, -- Marcin Makowski Ph.D. student in Theoretical Chemistry, Jagellonian University > Dear CCL-ers, > > Recently I encountered the following problem. When calculating (by > Gaussian 98) excited states of a molecule optimized with imposed D2d > symmetry constrain I got the strange features of the calculated excited > states. Namely, I got different calculated energies and (sometimes) > quite different oscillator strength for degenerate transitions. > Nevertheless, Gaussian denotes excited states being degenerate and > having E-symmetry. Can anybody explain me why is it so? > > Best regards, > Igor. > > > -= This is automatically added to each message by mailing script =- To > send e-mail to subscribers of CCL put the string CCL: on your Subject: > line and send your message to: CHEMISTRY_at_ccl.net > > Send your subscription/unsubscription requests to: > CHEMISTRY-REQUEST_at_ccl.net HOME Page: http://www.ccl.net | Jobs Page: > http://www.ccl.net/jobs > > If your mail is bouncing from CCL.NET domain send it to the maintainer: > Jan Labanowski, jkl_at_ccl.net (read about it on CCL Home Page) > -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ From chemistry-request@ccl.net Mon Jul 21 15:34:15 2003 Received: from brass.metals.hope.edu (brass.metals.hope.edu [198.110.98.36]) by server.ccl.net (8.12.8/8.12.8) with SMTP id h6LJYFjr019644 for ; Mon, 21 Jul 2003 15:34:15 -0400 Received: from hope.edu ([198.110.98.17]) by brass.metals.hope.edu (SAVSMTP 3.1.0.29) with SMTP id M2003072115340415840 ; Mon, 21 Jul 2003 15:34:04 -0400 Received: from [198.110.101.2] (polik$at$hope.edu) by hope.edu; Mon, 21 Jul 2003 15:34:16 -0400 X-WM-Posted-At: hope.edu; Mon, 21 Jul 03 15:34:16 -0400 Message-Id: <5.2.0.9.2.20030721152810.02920ac0$at$webmail.hope.edu> X-Sender: polik$at$webmail.hope.edu (Unverified) X-Mailer: QUALCOMM Windows Eudora Version 5.2.0.9 Date: Mon, 21 Jul 2003 15:31:04 -0400 To: chemistry$at$ccl.net From: "William F. Polik" Subject: WebMO 3.3: WWW-based interface to Gaussian, MOPAC, and GAMESS Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed WebMO version 3.3 has been officially released and is available for download at the WebMO website. A tour of screenshots, a working demo server, a detailed features list, and download information can be found at http://www.webmo.net WebMO is a FREE web-based interface to popular computational chemistry programs including Gaussian, MOPAC, and GAMESS. WebMO permits users to build 3-D molecular structures, submit multiple jobs, monitor job progress, and view text and graphical results all from within a standard web-browser. WebMO is ideal both for research and for classroom use. The WebMO feature list includes: * Integrated 3-D molecular editor with automatic clean-up and fragment library * Calculation of molecular energy, optimized geometry, transition states, vibrational frequencies and intensities, NMR frequencies, UV-vis frequencies, coordinate scans, IRC scans, saddle calculations, and molecular orbitals * Complete control over all submitted jobs, included automatic queuing, user time limits, and job archiving * Visualization of geometry, dipole moment, partial charges, normal modes, IR spectra, UV-vis spectra, infrared spectra, coordinate scans (pro), and molecular orbitals (pro) Features of WebMO new to versions 3.2 and 3.3 include: * Enhanced control over visualization of IR and NMR spectra * Enhanced control over visualization of molecular vibrations * Calculation and visualization of UV-vis spectra * Visualization of electron density, electrostatic potential,and electrophilic/nucleophilic surfaces (pro) * Import existing structures in MOL, PDB, and XYZ format * Import existing structures from gaussian and mopac input files * Export structures in MOL, PDB, XYZ, gaussian, or mopac formats * Integration with external visualization (chime, rasmol) and analysis (molden, molekel) programs (pro) WebMO has been adopted by hundreds of academic and professional users because it lowers the cost and greatly simplifies the implementation of computational chemistry: * All calculations are setup, run, and visualized using a standard web browser * One familiar interface supports many state-of-the-art computational chemistry programs * WebMO is accessible from dorms, labs, home, or anywhere with a web browser * WebMO is free, as are some of the supported computational chemistry programs * Only one server computer is required, rather than multiple workstations in a computer lab * A WebMO User's Guide containing instructions, tutorials, and class-tested student exercises is available for free download Try out WebMO for free by visiting the WebMO Working Demo at http://www.webmo.net/demo Since WebMO is a web-based product, there is no need to install any software on your computer. Just point, click, and compute! Enjoy! The WebMO Team From chemistry-request@ccl.net Mon Jul 21 11:45:48 2003 Received: from crane2.cf.ac.uk (crane2.cf.ac.uk [131.251.0.25]) by server.ccl.net (8.12.8/8.12.8) with ESMTP id h6LFjmjq011796 for ; Mon, 21 Jul 2003 11:45:48 -0400 Received: from thor.cf.ac.uk ([131.251.0.1]) by crane2.cf.ac.uk with esmtp (Exim 4.05) id 19ecrD-00077V-00 for chemistry^at^ccl.net; Mon, 21 Jul 2003 16:45:47 +0100 Received: from localhost (sacjap@localhost) by thor.cf.ac.uk (8.8.8/8.6.12) with ESMTP id QAA15834 for ; Mon, 21 Jul 2003 16:45:47 +0100 (BST) Date: Mon, 21 Jul 2003 16:45:47 +0100 (BST) From: Jamie Platts X-X-Sender: sacjap@thor To: chemistry^at^ccl.net Subject: CAS-SCF active space Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi Folks - I wonder if I can ask your advice on selecting active spaces for CAS-SCF calculations. I have a system which wants to form a broken- symmetry singlet UHF wavefunction, rather than the expected RHF one. The natural orbitals from this (152 e) UHF wavefunction look like: 71 72 73 74 75 EIGENVALUES -- 1.97076 1.95176 1.94478 1.78912 1.46209 76 77 78 79 80 EIGENVALUES -- 1.22142 0.77858 0.53791 0.21088 0.05522 Can I safely ignore everything up to 73, and use a (6,6) active space made up of 74 to 79? Or is 1.95/0.05 too big to ignore? Many thanks in advance, Jamie ---------------------------------------------------------- Jamie Platts Dept. of Chemistry Phone: +44 (0) 2920 874950 Cardiff University Email: platts^at^cf.ac.uk P.O. Box 912 FAX: +44 (0) 2920 874030 Cardiff CF10 3TB www.cf.ac.uk/chemy