From chemistry-request@www.ccl.net Mon Jan 4 05:24:28 1999 Received: from alpha.luc.ac.be (alpha.luc.ac.be [193.190.2.30]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with ESMTP id FAA23624 Mon, 4 Jan 1999 05:24:27 -0500 (EST) Received: from alpha (alpha [193.190.2.30]) by alpha.luc.ac.be (8.9.1/8.9.1) with ESMTP id LAA11184 for ; Mon, 4 Jan 1999 11:24:27 +0100 (MET) Date: Mon, 4 Jan 1999 11:24:27 +0100 (MET) From: Sergiusz Kwasniewski To: CCL Subject: Vibrational spectra Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Let's start with the most common sentence nowadays : Happy New Year ! Does anyone know how to calculate excitation spectra ? And what kind of program would you prefer ? We've been using MOPAC here (semi-empirical techniques) to run MECI calculations. In the end we want to be able to calculate UV/Vis absorption spectra. We were also thinking about buying Hyperchem (if there are versions for workstations available that is). I think I read somewhere that the calculations of certain spectra is included in this. Does anyone has another suggestion for programs/methods to use, or some pros/contras on MOPAC and Hyperchem ? Thank you. S. Kwasniewski ****************************** Sergiusz P. Kwasniewski Limburgs Universitair Centrum Universitaire Campus, Gebouw D 3590 Diepenbeek Tel. (+32) (0)11/26.83.15 Fax. (+32) (0)11/26.83.01 e-mail: skwasnie@luc.ac.be ****************************** From chemistry-request@www.ccl.net Mon Jan 4 10:02:32 1999 Received: from alpha.luc.ac.be (alpha.luc.ac.be [193.190.2.30]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with ESMTP id KAA24895 Mon, 4 Jan 1999 10:02:31 -0500 (EST) Received: from alpha (alpha [193.190.2.30]) by alpha.luc.ac.be (8.9.1/8.9.1) with ESMTP id QAA31327 for ; Mon, 4 Jan 1999 16:02:32 +0100 (MET) Date: Mon, 4 Jan 1999 16:02:31 +0100 (MET) From: Sergiusz Kwasniewski To: CCL Subject: RPA with AM1 Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi, Did anyone try to combine RPA(random phase approximation) with AM1 - a bit like the OVGF with AM1 for the ionization potentials, which worked quite well. Bye S. Kwasniewski ****************************** Sergiusz P. Kwasniewski Limburgs Universitair Centrum Universitaire Campus, Gebouw D 3590 Diepenbeek Tel. (+32) (0)11/26.83.15 Fax. (+32) (0)11/26.83.01 e-mail: skwasnie@luc.ac.be ****************************** From chemistry-request@www.ccl.net Mon Jan 4 11:03:05 1999 Received: from mail.zrz.TU-Berlin.DE (mail.zrz.TU-Berlin.DE [130.149.4.15]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with ESMTP id LAA25535 Mon, 4 Jan 1999 11:03:04 -0500 (EST) Received: from argon.chem.tu-berlin.de by mail.zrz.TU-Berlin.DE with SMTP (IC-PP); Mon, 4 Jan 1999 17:02:28 +0100 Received: by argon.chem.tu-berlin.de (AIX 3.2/UCB 5.64/ZRZ-AIX) id AA18300; Mon, 4 Jan 1999 17:03:50 +0100 From: Wolfram Koch Message-Id: <9901041603.AA18300@argon.chem.tu-berlin.de> Subject: RECP for KS-DFT To: chemistry@www.ccl.net Date: Mon, 4 Jan 1999 17:03:50 +0100 (NFT) X-Mailer: ELM [version 2.4 PL23] Content-Type: text Hi there, just a quick question: Are there systematic studies of the applicability of (R)ECPs designed with conventional wave function based methods (such as the Hay-Wadt ot Stuttgart ECPs) to Kohn-Sham DFT? We all assume that it works and I just wonder whether someone explicitly checked it. If there is interest, I'll summarize. Thanks in advance, Wolfram -- _________________________________________________________________________ Prof. Dr. Wolfram Koch Institut fuer Organische Chemie, Sekr.C3 Technische Universitaet Berlin Strasse des 17.Juni 135, D-10623 Berlin Fon: +49 30 314 27870, Fax: +49 30 314 21102 e-mail: kochw@argon.chem.TU-Berlin.DE _________________________________________________________________________ From chemistry-request@www.ccl.net Mon Jan 4 21:18:21 1999 Received: from mail-01.telis.org (mail-01.telis.org [204.71.76.230]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with ESMTP id VAA06385 Mon, 4 Jan 1999 21:18:20 -0500 (EST) Received: from [207.49.120.40] (s21-pm01.snaustel.campuscwix.net [207.49.120.40]) by mail-01.telis.org (8.9.0/8.8.8) with ESMTP id SAA02658 for ; Mon, 4 Jan 1999 18:15:09 -0800 (PST) X-Sender: gammadas@mail.telis.org Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 4 Jan 1999 20:15:55 -0600 To: chemistry@www.ccl.net From: Goutam Das Subject: complex geom calcn protocol A little over a week ago, I posted a question regarding a protocol for calculating complex geometry and eventually the global minima. Here is my original query and the responses. I thank everyone who responded . I wonder whether there are protocols (besides MD sim) for calculating geometries (ab initio/semiempiric/molmech) of minima's and finally glob minimas for pairs of simple molecules. If there are, I would deeply appreciate if anyone could kindly point me to good references. Normally I optimize geom's of both mol's, then freeze the crd's of each and then move one relative to another and then relax all constraints, guessing inital geoms by intuition--I am sure I miss a lot of conf's and maybe certainly the glob min (although I understand that there is no guarantee that any particular method could give the global min). However, there should be a much better & efficient subroutine. If you have a MD program you can probably use the simulated annealing protocol where you slowly cool your system until it freezes in. If you do it very slow (a few ps) you will probably find the global minimum, if you do it fast you will find other minima too. The method is used a lot in refinement but useful for simple conformational searches too. GROMACS implements the method in MD simulations. http://rugmd0.chem.rug.nl/~gmx Groeten, David. ________________________________________________________________________ Dr. Ir. David van der Spoel Biomedical center, Dept. of Biochemistry s-mail: Husargatan 3, Box 576, 75123 Uppsala, Sweden phone: 46 18 471 4205 fax: 46 18 511 755 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ You sure do miss a lot of conformations. However the problem is non trivial and to my knowledge has not been solved for an arbitrary shaped molecule. If you think about it for a moment you will realize that there are 6 degrees of freedom for the interaction of two molecules(imagine one fixed at the origin and the other rotating and translating about it). This already gives you millions of conformations to check. Add to that the internal degrees of freedom for rotation about single bonds and the problem becomes intractable. The best we have done here is a Monte Carlo simulated annealing of a dimer with internal bond rotations. It works well, but there is no guarantee we have found all the important local minima when the number of internal bond rotations is large. JERRY -- ************** Jerry Perlstein Center for Photoinduced Charge Transfer Department of Chemistry University of Rochester Rochester,NY 14627-0216 Tel: (716)275-2511 FAX: (716)242-9485 perlstein@chem.chem.rochester.edu http://www.chem.rochester.edu/~stc/perlstein.html GOUTAM DAS, Ph.D BETZDEARBORN (A division of Hercules) PO BOX 4300, 9669 GROGANS MILL ROAD THE WOODLANDS, TX 77387-4300 # 281.367.6201 xt 425///email:gammadas@telis.org