LIST OF POSTERS Potential-energy Surface Intersections for Triatomic Molecules I. M. Mills R. N. Dixon and S. Carter Unitw-sity of Reading Distributed Multipoles from partitioning by Zero-flux Surfaces D. L. Cooper Universify qf Ulcj’ord N. C. J. Stutchbury ICI Macclesjield and D. G. Bounds Continuum States of the Hydrogen Molecule J. Tennyson and C. J. Noble Daresbury Luboratory Warrington Analysis of Interbond Interactions Theory and Application in Ab Znitio and Semi-empirical Schemes of Calculation P. R. Surjan G. Naray-Szabo and I. Mayer Chinoin Budapest Hungury A New Potential Surface for Ff H + HFfH J. S. Wright and R. J. Williams Carlcton University Ottawa Canada Hole Localisation in Ionised States of Ordered Solids :Cluster Calculations on Cuprous Halides G.Janssen and W. Nieuwpoort Unicersity of Groningen The Netherlands Hyperfine Splitting in the t-Butyl Radical R. E. Overill King’s College London Computations on the Cluster Photochemistry of Ammonia Water and Ammonia +Water Mixtures E. M. Evleth H. Z. Cao and E. Kassab UniversitP Paris VI France The Exact One-electron Schrodinger Model of Molecular Structure and the Molecular Envelope G. Hunter York University Downsview Ontario Canada Comparison of the Electronic Structures of V(0) Hal and P(0) Hal Analogues (Hal = F C1 Br) by Ultraviolet Photoelectron Spectroscopy and SCC -XaCalculations S. Elbel J. Kudnig G. Riinger and M. Grodzicki Uniziersity of Hamburg WesfGermany The Electronic Structure of the HCO+ Ion M. Hilczer and B.C. Webster University ojGlasgow Properties of the Vibrating Rotating Methane Molecule W. T. Raynes P. W. Fowler P. Lazzeretti and R. Zanasi University of Shefield Quantum-mechanical Approach to Infrared Intensities :The Nuclear Electric Shielding Tensor R. Zanasi and P. Lazzeretti University ofModenu Italy EXAFS Phase Shifts Evaluated from Cluster Calculations J. Paul Chalmers Unioersity oj’ Technology Goteborg Sweden Potential-energy Curves for Various C Il and A Molecular States of some Effective One- and Two-Electron Diatomic Systems Lil LiH+ Na NHe6+ LiH and NHe5+ Mme Frecon and A. Alikacem Universitk Cluudc Bernard Villeurbanne France 205 LIST OF POSTERS Calculation of the C,H Potential-energy Surface Using PAOs G. Chambaud H.Lavendy B. Pouilly J. M. Robbe E. Roueff and B. Levy ENSJF Mon tr ouge France Parity-violating Energy Differences and the Origins of Biomolecular Chirality G. E. Tranter University of Oxford An Ab Initio Study of the Excited States of A1F D. Hirst University of Warwick Valence-electron-only Calculations G. G. Balint-Kurti M. J. Davis T. P. Martin and A. H. Harker University of Bristol Theoretical Characterization of the Trifluoromethoxy Radical I. H. Williams and J. S. Francisco University of Cambridge Potential-energy Curves for Excited States of BeF C. Marian University of Bonn West Germany Investigation of the Reaction Pathway for the Formation of Urea C. Dijkgraaf DSM Geleen The Netherlands and A. D. Buckingham N. C. Handy and J. E. Rice University of Cambridge Structure Dipole-moment Derivatives and Infrared Intensity of Dimers of H,O and H,S R. D. Amos University of Cambridge Intermolecular Perturbation Theory Applications to some Hydrogen-bonded van der Waals Molecules A. J. Stone and G. J. B. Hurst University of Cambridge Reaction Paths Hamiltonian Study of the Isomerisation of the Methoxy Radical S. M. Colwell University of Cambridge The Calculation of CI Gradients and Molecular Properties J. E. Rice University of Cambridge Artefact-free Models of Molecular Structures of Polyatomics P. G. Burton University of Wollongong New South Wales Australia