FARADAY DISCUSSIONS OF THE CHEMICAL SOCIETY NO. 62 1977 Potential Energy Surfaces THE FARADAY DIVISION CHEMICAL SOCIETY LONDONFARADAY DISCUSSIONS OF THE CHEMICAL SOCIETY NO. 62 1977 Potential Energy Surfaces THE FARADAY DIVISION CHEMICAL SOCIETY LONDONA GENERAL DISCUSSION ON Potential Energy SurJaces Sth, 9th and 10th September, 1976 A GENERAL DISCUSSION on Potential Energy Surfaces was held in the School of Molecular Sciences at the University of Sussex on Sth, 9th and 10th September, 1976. The President of the Faraday Division, Professor D. H. Everett M.B.E., was in the chair: about 160 Fellows of the Faraday Division and visitors from overseas attended the meeting. Among the overseas visitors were: Prof. V. Aquilanti, Italy Miss B. A. Blackwell, Canada Mr. J.Bruinsma, The Netherlands Prof. D. L. Bunker, U.S.A. Dr. J. J. Burton, U.S.A. Mr. S . Carley, Canada Dr. hl. J. Coggiola, U.S.A. Prof. M. Daniels, U.S.A. Prof. D. H. W. den Boer, The Netherlands Dr. P. J. Derrick, Australia Prof. M. J. S. Dewar, U S A . Dr. A. Ding, West Germany Dr. D. A. Dixon, U.S.A. Mr. D. J. Douglas, Canada Dr. 1. R. Elsum, U.S.A. Dr. F. Engelke, West Germany Prof. K. Freed, U.S.A. Prof. T. F. George, U.S.A. Dr. D. W. Gough, Canada Mr. S . Goursaud, France Dr. K. D. Hansel, West Germany Prof. W. L. Hase, U S A . Dr. E. F. Hayes, U.S.A. Prof. D. R. Herschbach, U.S.A. Prof. D. V. S . Jain, India Dr. 0. Kafri, U.S.A. Dr. B. Katz, Israel Prof. W. Klemperer, U.S.A. Dr. A. Komornicki, U.S.A. Prof. K. Kuchitsu, Japan Dr. J. P. Kuntz, West Germany Prof. W.Kutzelnigg, West Germany Dr. U. T. Lamanna, Italy Dr. S . Leach, France Prof. R. J. Le Roy, Canada Dr. H. J. Loesch, West Germany Mrs C . M. Meerman van Benthem, Dr. V. Menendez, Spain Prof. W. H. Miller, U.S.A. Dr. D. N. Mitchell, Canada Dr. J. J. C. Mulder, The Netherlands Prof. E. A. Ogryzlo, Canada Dr. F. Pirani, Italy Prof. J. C . Polanyi, Canada Dr. L. L. Poulsen, Denmark Dr. K. Rasmussen, Denmark Prof. H. F. Schaefer, U.S.A. Dr. K. Shobatake, West Germany Mrs Sizun, France Dr. J. J. Sloan, Canada Dr. W. Thiel, West Germany Prof. J. Tomasi, Italy Prof. J. Troe, West Germany Dr. T. Valencich, U.S.A. Mr. J. J. Valentini, U.S.A. Mr. M. C. van Hemert, The Netherlands Prof. V. Vecchiocattivi, Italy Dr. J. C. Whitehead, U.S.A. Dr. P. E. S . Wormer, The Netherlands Prof.R. E. Wyatt, U.S.A. Dr. A. P. Zandee, The Netherlands TJie NetherlandsISBN: 0 85186 918 1 ISSN: 0301-7249 0 The Chemical Society and Contributors 1977 Printed in Great Britain by Richard Clay (The Chaucer Press), Ltd., Bungay, SuffolkCONTENTS Page 7 20- 29 40 47 59 67 77 92 110 127 138 169 179 185 197 210 Pot en tial Surfaces from Vibra t ion-ro tat ion Data by I. M. Mills Experimental Determination of Average and Equilibrium Structures of Polyatomic Gas Molecules by Diffraction and Spectroscopic Methods by K. Kuchitsu and K. Oyanagi Semi-classical Methods for Vibrational Energy Levels of triatomic molecules by N. C. Handy, S. M. Colwell and W. H. Miller Semi-classical Theory for Non-separable Systems by W. €3. Miller GENERAL DISCUSSION Potential Energy Surfaces for Ion-molecule Reactions by C.F. Bender, J. H. Meadows and H. F. Schaefer An Ab Initio Potential Surfacesfor the Reaction N+ + H, -+ NH+ + H by M. A. Gittins, D. M. Hirst and M. F. Guest Potential Energy Surfaces for Simple Chemical Reactions by G. G. Baht-Kurti and R. N. Yardley A Many-body Expansion of Polyatomic Potential Energy Surfaces: Applica- tion to H,, Systems by A. J. C. Varandas and J. N. Murrell Potential Energy Surface for Bond Exchange Among Three Hydrogen Molecules by D. A. Dixon, R. M. Stevens and D. R. Herschbach A New Empirical Potential Hypersurface for Bimoleczilar Reaction Systems by 0. Kafri and M. J. Berry GENERAL DISCUSSION DeterminiiTg Anisotropic Intermolecular Potentials for Van der Waals Molecules by R.J. Le Roy, J. S. Carley and J. E. Grabenstetter Tjie Rotational Spectroscopy of Van der Waals Molecules by W. Klemperer Q uan tum Chemical Calculation of In te rm o lecular Interact ion Po tent ials, Mainly of Van der Waals Type by W. Kutzelnigg Studies of the mechanisms of Some Organic Reactions and Photoreactions by Semi-empirical SCF MO Methods by M. J. S. Dewar Ethyl Radical Potential Energy Surface by C. S. Sloane and W. L. Hase6 CONTENTS 222 232 246 255 267 29 1 300 347 The Four-centre Reaction 12* -t F2 Studied by Laser-indirced Cherni- luminescence in Molecular Beams by F. Engelke, J. C. Whitehead and R. N. Zare Crossed Beam Studies of Endoergic Biinolecular Reactions: Production of Stable Trihalogen Radicals by J. J. Valentini, M. J. Coggiola and Y. T. Lee Radiative Transitions for Molecular Collisions in an Intense Laser Field by T. F. George, J.-M. Yuan, I. H. Zimmerman and J. R. Laing Alkali Atom-dimer Exchange Reactions: Na +- Rb2 by D. J. Mascord, P. A. Gorry and R. Grice The Reaction of F + H2 4 HF + H by J. C. Polanyi and J. L. Schreiber The Scattering of Hg(63P2) by CO, N2 and C 0 2 by J. Costello, M. A. D. Fluendy and K. P. Lawley GENERAL DISCUSSION Closing Remarks by H. C. Longuet-Higgins * The author to whom correspondence should be addressed is indicated by an asterisk after his name in the heading of each paper.