From mjchoi@kistmail.kist.re.kr Fri Dec 1 02:55:35 1995 Received: from garam.kreonet.re.kr for mjchoi@kistmail.kist.re.kr by www.ccl.net (8.6.10/950822.1) id CAA19784; Fri, 1 Dec 1995 02:55:32 -0500 Received: from kistmail.kist.re.kr ([161.122.12.3]) by garam.kreonet.re.kr (8.6.9H1/8.6.12) with SMTP id QAA10552 for ; Fri, 1 Dec 1995 16:55:04 +0900 Received: from indigo2.kist.re.kr by kistmail.kist.re.kr (5.65/KISTMAIL-0.1) id AA20260; Fri, 1 Dec 95 16:54:35 +0900 Sender: mjchoi@kistmail.kist.re.kr Message-Id: <2EDE7130.41C6@kistmail.kist.re.kr> Date: Thu, 01 Dec 1994 16:58:24 -0800 From: "choi, mun-jeong" Organization: DCC, KIST To: chemistry@www.ccl.net Subject: Gill-Murray local minimization procedure Dear netters, I am looking for Gill-Murray local minimization procedure (Gill, P.E.; Murray, W. Math.Prog. 1974, Vol.7, 311). I can't get this paper within several days. If you know it, let me know. Thanks in advance. e-mail: mjchoi@indigo2.kist.re.kr From smb@smb.chem.niu.edu Fri Dec 1 09:31:03 1995 Received: from mp.cs.niu.edu for smb@smb.chem.niu.edu by www.ccl.net (8.6.10/950822.1) id JAA24519; Fri, 1 Dec 1995 09:31:02 -0500 Received: from cz2.chem.niu.edu by mp.cs.niu.edu with SMTP id AA03281 (5.67b/IDA-1.5 for <@mp.cs.niu.edu.chem.niu.edu:CHEMISTRY@www.ccl.net>); Fri, 1 Dec 1995 08:31:02 -0600 Received: from smb.chem.niu.edu by cz2.chem.niu.edu via SMTP (920330.SGI/890607.SGI) (for @mp.cs.niu.edu.chem.niu.edu:CHEMISTRY@www.ccl.net) id AA23443; Fri, 1 Dec 95 07:52:59 -0600 Received: by smb.chem.niu.edu (920330.SGI/890607.SGI) (for @cz2.chem.niu.edu:CHEMISTRY@www.ccl.net) id AA09290; Fri, 1 Dec 95 07:52:58 -0600 Date: Fri, 1 Dec 95 07:52:58 -0600 From: smb@smb.chem.niu.edu (Steven Bachrach) Message-Id: <9512011352.AA09290@smb.chem.niu.edu> To: CHEMISTRY@www.ccl.net Subject: Re: CCL:combining different basis sets - an addition > It of course depends on what you mean with "better". The SCF will >minimize the energy, adding any new function should give an energy closer >to the HF limit. However, most of the time this is not really interesting. >When you want energies, you usually want relative energies, and then it's >quite important that you make the same approximations, that is, calculate >at a constant level of theory, so that systematic errors cancel. Also, as >you said in the part of the message I deleted, adding functions in an >unbalanced way will definitely affect the charge distribution, probably not >making it "better" :-) Specific questions can sometimes be answered by >including functions that are not atom-centered, but then you get the >problem of findning a completely reproducable way of doing that for any >system. I hate to bring up this topic yet again on this list, but it strikes a nasty chord in me. The whole problem rests on this idea of what's "better". How does one decide what is a "better" charge distribution? There is no experimental test, except to compare the full spatial distribution determined by calculations with those determined experimentally (like an x-ray diffraction - but resolution is a problem). Usually, the idea of "better" charge distribution are numbers that make more intuitive sense according to the researcher - hardly an non-empirical basis. On the other hand, there is no question about the effects of added functions with regards to energy - added functions WILL lower the energy every time, sometimes not by much, but lower. And since the HF wavefunction is variational, the lower the better! Keep in mind, as Mulliken pointed out in the 50s, that one can construct a perfectly good, HF-limit wavefunction for H2 by placing a huge set of orbitals centered only on one of the hydrogens. A mulliken population for this system would be meaningless in any intuitive sense (one hydrogen has a charge of +1, the other a charge of -1), yet the energy and the (patial) density distribution are at the HF limit. Steve Steven Bachrach Department of Chemistry Northern Illinois University DeKalb, Il 60115 Phone: (815)753-6863 smb@smb.chem.niu.edu Fax: (815)753-4802 From owner-chemistry@ccl.net Fri Dec 1 10:43:17 1995 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.6.10/950822.1) id KAA26223; Fri, 1 Dec 1995 10:43:16 -0500 Received: from struve.pdc.kth.se for teoulf@pdc.kth.se by bedrock.ccl.net (8.7.1/950822.1) id KAA13859; Fri, 1 Dec 1995 10:43:12 -0500 (EST) Received: (from teoulf@localhost) by struve.pdc.kth.se (8.6.10/8.6.9) id QAA34604 for chemistry@ccl.net; Fri, 1 Dec 1995 16:43:10 +0100 Date: Fri, 1 Dec 1995 16:43:10 +0100 From: Ulf Ryde Message-Id: <199512011543.QAA34604@struve.pdc.kth.se> To: chemistry@ccl.net Subject: G94: B3LYP energy and Charge Dear CCL'ers, I have just started to use Gaussian, and I have noted two strange things with G94: (I sent this question to info@gaussian.com two weeks ago, but I have got no answer) 1. Gaussian does not give the same B3LYP energy as IBM:s Mulliken. Who is right? Example: H2O, 6-31G* basis (the same grid is used, and the programs give identical result at the HF level): Mulliken: -76.369843 (xfine grid = -96032) Gaussian: -76.407530 Gaussian input: #P B3LYP/6-31g* SCF=Tight Int(Grid=-96032) H2O, C2v, 6-31g*, 29/11-95 0 1 O .00000000000000 .00000000000000 -.06267499849443 H1 -.75848155567836 .00000000000000 .49741677376896 H2 .75848155567836 .00000000000000 .49741677376896 ---------------------------------------------------------------------------- 2. Charge behaves strangely: Example: #P HF/6-31G* Charge Prop=EFG SCF=Tight NoSymm H2O + 7 point charges, 6-31G*, 15/11-95 0 1 O -1.34200000000000 -.93300000000000 1.63800000000000 H1 -1.86100000000000 -.36800000000000 2.19900000000000 H2 -1.83700000000000 -1.73600000000000 1.48900000000000 ! Charge .54991052143234 -9.77744686560452 -1.08659295472025 -.32000 1.39650816267525 -8.07669267560759 -1.29068345751988 .24000 -2.23176744265151 -10.02122163283741 -1.17541011797565 -.00100 -2.82892113602821 -11.42717842990153 .19275214153298 .06100 -3.66229068912670 -7.59292259489736 -.57069751708786 .00800 -2.85159785856150 -6.02633901322242 -1.63272402239704 .06100 -5.64650391078977 -7.78945419018589 -1.10926967725355 .06100 This input gives an SCF energy of -79.344513 au while other programs e.g. Turbomole and Molcas give -76.049928. The total nuclear repulsion energy is the same in all programs. If the last charge is removed, all programs give the SCF energy -76.0515598 au. Is this a (known) bug or is it a problem of our installation? Best Regards Ulf --------------------------------------------------------------- Dr. Ulf Ryde teoulf@garm.teokem.lu.se Assistant professor Department of Theoretical Chemistry University of Lund Chemical centre, P. O. Box 124 Tel: +46-46-2224502 S-221 00, Lund, SWEDEN Fax: +46-46-2224543 --------------------------------------------------------------- From /G=Matthew/S=Harbowy/OU=LIPTONUS-EC02/O=TMUS.TJL/@LANGATE.gb.sprint.com Mon Dec 4 09:56:00 1995 Received: from reston-mx1.telemail.net for /G=Matthew/S=Harbowy/OU=LIPTONUS-EC02/O=TMUS.TJL/@LANGATE.gb.sprint.com by www.ccl.net (8.6.10/950822.1) id JAA12319; Mon, 4 Dec 1995 09:55:58 -0500 From: Date: Mon, 4 Dec 1995 09:53:00 -0500 X400-Originator: /G=Matthew/S=Harbowy/OU=LIPTONUS-EC02/O=TMUS.TJL/@LANGATE.gb.sprint.com X400-MTS-Identifier: [/PRMD=LANGATE/ADMD=TELEMAIL/C=GB/;Mon Dec 4 09:53:55 199500] X400-Content-Type: P2-1984 (2) Content-Identifier: Re: CCL:M:(1)Koo Message-ID: <"Mon Dec 4 09:53:55 199500*/G=Matthew/S=Harbowy/OU=LIPTONUS-EC02/O=TMUS.TJL/PRMD=LANGATE/ADMD=TELEMAIL/C=GB/"@MHS> To: CHEMISTRY@www.ccl.net Subject: Re: CCL:M:(1)Koopman's Theorem and (2)BondingREAD/NEW >(2) I use CAChe MOAPC to calculate the distances and bond orders between the 3 >hydrogens of a NH3 right above the pai ring of ferulic acid (4-OH-3-OCH3- >cinnamic acid). After geometry optimization, NH3 shifts to the edge of the >pai-ring. I did this calculation in 3 ways: 1) no bonding is specified between >H's of NH3 and pai-ring; 2) 1 H of NH3 hydrogen-bonded to carbons #1,3,5 (if >the 6 C's are numbered 1 to 6); 3) 3 H's of NH3 hydrogen-bonded to C's #1,3,5, >respectively. My question is: Does the calculation take into account whether I >specified the bonding at all? It seems it doesn't. The results always show >small bond order between H's of NH3 and substituents of the ring AND EVEN >SMALLER bond order between those H's of NH3 and C's of the ring, regardless of >whether I draw hydrogen bond lines in the CAChe Editor (Graphic Interface for >MOPAC). Seems MOPAC Input doesn't have bond information. I guess specifying >bonds in Editor doesn't do anything at all. Can someone clarify this for me? One of the big flaws of a graphical interface is the thinking that the graphics themselves have meaning. This is especially true for semiempirical and ab-initio schemes. Unless you do something to lock a particular conformation, risking locking it into a non-minimum conformation, all the atoms are 'free' to do whatever they want in a minimization. There's no such thing as a bond, especially a hydrogen bond, outside of the 'bonding state' generated by a particular agreeable overlap of orbitals. Try drawing a molecule with every atom bonded to every other atom, and you'll get the same result as bonding no atoms to any other atom in the graphical interface for MOPAC. Molecular mechanics, on the other hand, is a whole different story. matt