From taisung@chem.duke.edu Mon Jan 5 15:13:05 1998 Received: from chem.duke.edu for taisung@chem.duke.edu by www.ccl.net (8.8.3/950822.1) id OAA10409; Mon, 5 Jan 1998 14:56:54 -0500 (EST) Received: from density.chem.duke.edu (density.chem.duke.edu [152.3.169.4]) by chem.duke.edu (8.7.4/Duke-1.1) with SMTP id OAA09737; Mon, 5 Jan 1998 14:56:55 -0500 (EST) Date: Mon, 5 Jan 1998 14:56:54 -0500 (EST) From: Taisung Lee To: computational chemistry list Subject: Question: the nuclear-nuclear interaction in MOPAC Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi Everyone, I got a question about the nuclear-nuclear interaction in MOPAC program. I couldn't find Dr. James Stewart's email address. If anyone here can answer my question or forward Dr. Stewart's email address to me, I really appreciate. I found in the MOPAC93 R2 manual p115, the core-core term in MNDO for NH/OH pair is in the form of Eab=ZaZb(1 + exp( -Rab*Ab) / Rab + exp( -Rab*Aa) )--(1) while in the MOPAC program (subroutine rotate.f) and in the orginal MNDO paper (JACS 99 4899 (1977)) this term is in the form of Eab=ZaZb(1 + exp( -Rab*Ab) * Rab + exp( -Rab*Aa) )--(2) They give quite different answers. Could anyone tell me which is the correct one? Thanks in advance. Taisung Lee Research Associate Department of Chemistry Duke University taisung@chem.duke.edu From genghis@darkwing.uoregon.edu Mon Jan 5 16:13:07 1998 Received: from darkwing.uoregon.edu for genghis@darkwing.uoregon.edu by www.ccl.net (8.8.3/950822.1) id PAA10507; Mon, 5 Jan 1998 15:15:00 -0500 (EST) Received: from localhost (genghis@localhost) by darkwing.uoregon.edu (8.8.8/8.8.8) with SMTP id MAA02650 for ; Mon, 5 Jan 1998 12:15:00 -0800 (PST) Date: Mon, 5 Jan 1998 12:14:59 -0800 (PST) From: "Dale A. Braden" To: cclpost Subject: Summary: variation of B3LYP parameters Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Dear CCL, Many thanks to all who responded to my question about varying the three parameters in the hybrid DFT functionals: Original question: "Does anyone know of any references to studies in which the three parameters in the B3LYP (or similar) density functionals were varied? "Although the optimized parameter values for the B3-hybrids were based upon fits to experimental data for a set of molecules which did not contain any transition metals, the B3-hybrids have been used with some success in modelling transition metal-containing compounds as well. However, wouldn't one expect much better results if a new parameter set for transition metals could be determined?" In summary, there are no published data yet, although there are at least two studies about to be published. Efforts have been mostly directed at developing entirely new functionals-- see A.D. Becke, J. Chem. Phys. 107 (1997) 8554. However, the new functionals are optimized for organic molecules-- no transition metals are in the training set. Thus, there is still a need, I think, for developing optimized parameters for transition metal compounds. The problem, I suppose, is gathering together thermochemical data for TM compounds that is as accurate as that for the G1 and G2 molecule sets. Best wishes to all, Dale Dale Braden Department of Chemistry University of Oregon Eugene, OR 97403-1253 genghis@darkwing.uoregon.edu From boufer@cennas.nhmfl.gov Mon Jan 5 19:13:07 1998 Received: from cennas.nhmfl.gov for boufer@cennas.nhmfl.gov by www.ccl.net (8.8.3/950822.1) id SAA11570; Mon, 5 Jan 1998 18:56:16 -0500 (EST) Received: from localhost (boufer@localhost) by cennas.nhmfl.gov (8.8.5/8.8.5) with SMTP id SAA28475 for ; Mon, 5 Jan 1998 18:56:01 -0500 (EST) Date: Mon, 5 Jan 1998 18:56:00 -0500 (EST) From: Ahmed Bouferguene X-Sender: boufer@cennas To: chemistry@www.ccl.net Subject: From XYZ to spherical harmonics Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Greetings all, Does anybody know a reference giving the recipe allowing to go from x^u y^v z^w exp(-a r^2) to a linear combination of r^t Y_{lm} (theta, phi) exp(-a r^2) Thanks for your help. -- Ahmed Bouferguene