From jstewart&$at$&fujitsu.fai.com Thu Jan 27 18:45:34 1994 Received: from mail.barrnet.net for jstewart ":at:" fujitsu.fai.com by www.ccl.net (8.6.4/930601.1506) id SAA06522; Thu, 27 Jan 1994 18:26:53 -0500 Received: from fujitsu1.fai.com by mail.barrnet.net (5.67/1.37) id AA17104; Thu, 27 Jan 94 15:26:53 -0800 Received: by fujitsu.fai.com (4.1/SMI-4.1) id AA21007; Thu, 27 Jan 94 08:48:22 PST Date: Thu, 27 Jan 94 08:48:22 PST From: jstewart.,at,.fujitsu.fai.com (Dr. James Stewart) Message-Id: <9401271648.AA21007 \\at// fujitsu.fai.com> To: chemistry&$at$&ccl.net Subject: Re: Difficult optimization in MOPAC I thank everyone who sent me suggestions on how to optimize the geometry of C6H5-COO radical using RHF techniques. The best suggestion was given by Dr John McKelvey. His solution to the problem is given in the following ARC file from MOPAC 93. The GNORM was reduced to below the pre-specified limit of 0.01, which is definitive proof of the validity of the optimization. About 5-7 days had been spent on attempting the optimization, without any success. Within a day of posting the problem, I had received the correct answer. This demonstrates the usefulness of the Net, and the skill of its users. Jimmy Stewart SUMMARY OF PM3 CALCULATION MOPAC 93.00 C7 H5 O2 Thu Jan 27 09:28:47 1994 GNORM=0.01 GRADIENTS PRECISE PM3 SHIFT=50 EF C.I.=(3,2) C6H5-COO(.) GEOMETRY OPTIMISED USING EIGENVECTOR FOLLOWING (EF). SCF FIELD WAS ACHIEVED HEAT OF FORMATION = -10.726466 KCAL = -44.87954 KJ ELECTRONIC ENERGY = -6178.829220 EV STATE: DOUBLET B2 CORE-CORE REPULSION = 4687.367953 EV GRADIENT NORM = 0.009496 DIPOLE = 4.39069 DEBYE SYMMETRY: C2v NO. OF FILLED LEVELS = 22 AND NO. OF OPEN LEVELS = 1 CONFIGURATION INTERACTION WAS USED IONIZATION POTENTIAL = 10.354278 EV HOMO (SOMO) LUMO (EV) = -10.439 ( -7.018) -0.921 MOLECULAR WEIGHT = 121.115 SCF CALCULATIONS = 17 COMPUTATION TIME = 12 MINUTES AND 10.633 SECONDS FINAL GEOMETRY OBTAINED CHARGE GNORM=0.01 GRADIENTS PRECISE PM3 SHIFT=50 EF C.I.=(3,2) C6H5-COO(.) C 0.00000000 0 0.0000000 0 0.0000000 0 0 0 0 -0.0563 C 2.78147112 1 0.0000000 0 0.0000000 0 1 0 0 -0.1536 C 1.39164098 1 60.0624509 1 0.0000000 0 1 2 0 -0.1172 C 1.39164180 1 60.0622252 1 179.9992100 1 1 2 3 -0.1172 C 1.39738087 1 60.0816056 1 -0.0001412 1 2 1 3 -0.0343 C 1.39737820 1 60.0816087 1 -179.9989763 1 2 1 3 -0.0343 H 1.09548486 1 179.9966649 1 -103.5372856 1 1 2 3 0.1071 H 1.09537441 1 120.0286616 1 -179.9985171 1 3 1 2 0.1124 H 1.09537460 1 120.0285221 1 179.9985854 1 4 1 2 0.1124 H 1.09678871 1 120.1471184 1 179.9997238 1 5 2 1 0.1195 H 1.09678839 1 120.1472596 1 -179.9983554 1 6 2 1 0.1195 C 1.47024274 1 179.9997536 1 3.4455962 1 2 1 3 0.4514 O 1.26492843 1 130.2209371 1 -179.9902413 1 12 2 5 -0.2548 O 1.26492930 1 130.2194911 1 0.0089828 1 12 2 5 -0.2548 From billg%scg. ":at:" ":at:" ccl.net Thu Jan 27 22:45:00 1994 Received: from mail.barrnet.net for billg%scg.[ AT ][ AT ]ccl.net by www.ccl.net (8.6.4/930601.1506) id WAA08525; Thu, 27 Jan 1994 22:41:48 -0500 Received: from fujitsu1.fai.com by mail.barrnet.net (5.67/1.37) id AA18612; Thu, 27 Jan 94 19:41:34 -0800 Received: from scg.scg.fai.com by fujitsu.fai.com (4.1/SMI-4.1) id AA10706; Thu, 27 Jan 94 19:41:13 PST Received: by scg.scg.fai.com (4.1/SMI-4.1) id AA05161; Thu, 27 Jan 94 19:41:51 PST Date: Thu, 27 Jan 94 19:41:51 PST From: billg-!at!-scg.fai.com (Marketing) Message-Id: <9401280341.AA05161 |-at-| scg.scg.fai.com> To: admiraal- at -bio.vu.nl Subject: Perturbational MO References Cc: chemistry |-at-| ccl.net >I need information on using perturbuation theory (? I don't >know if this is the correct name) >for modelling interactions between organic molecules. >Thanks, Alex Here are three references on the subject of perturbational molecular orbital (PMO) theory. 1) Dewar, M. J. S., "The Molecular Orbital Theory of Organic Chemistry"; McGraw--Hill: New York, 1969. 2) Fukui, K. Acc. Chem. Res., 1971, vol. 4, p. 57. 3) Fleming, I. Frontier Orbitals and Organic Chemical Reactions"; Wiley-Interscience: London. I believe there is also a good reference by L. Salem which I cannot recall. PMO theory had its halcyon days about 20 years ago before computational chemistry codes and platforms were widely available. Today variational semiempirical (e.g., MNDO PM3, etc.) codes are often used instead since they can locate transition states (at least in principle) and even entire reaction pathways. Yet, for sheer insight into many types of concerted reactions, PMO theory offers a lot of bang for the buck! ********************************************************************* * William A. Glauser, Ph.D. | Internet: billg -x- at -x- scg.fai.com * * Computational Chemist | Voice: (610) 436-8125 * * SuperComputer Group | FAX: (610) 430-1526 * * Fujitsu America, Inc. |-----------------------------------* * 1564 McDaniel Drive | * * West Chester, PA 19380 | * *********************************************************************