These volumes contain the invited and contributed talks of the first general Conference of the Condensed Matter Division of the European Physical Society, which took place at the campus of the University of Antwerpen (Universitaire Instelling Antwerpen) from April 9 till 11, 1980. The invited talks give a broad perspective of the current state in Europe of research in condensed matter physics. New developments and advances in experiments as well as theory are reported for 28 topics. Some of these developments, such as the recent stabilization of mono-atomic hydrogen, with the challenging prospect of Bose condensation, can be considered as major break­ throughs in condensed matter physics. Of the 65 invited lecturers, 54 have submitted a manuscript. The remaining talks are published as abstracts. The contents of this first volume consists of 9 plenary papers. Among the topics treated in these papers are: - electronic structure computations of iron the density functional theory hydrogen in amorphous Si topologically disordered materials nuclear antiferromagnetism stabilization of mono-atomic hydrogen gas covalent and metallic glasses nonlinear excitations in ferroelectrics.

1. Metals and Alloys.- µSR and Muon Knight Shift Measurements on LaNI5Hx.- Trapping of Positive Muons in Dilute Aluminium Alloys.- A New Theoretical Approach to Calculate Total Energy Differences in Solids. Application for the Tetragonal Shear Moduli of fcc Transition Metals.- Evidence for Electron-Electron Scattering in Copper and Silver from Radio Frequency Size Effect Measurements.- New Evidence for Intersheet Electron-Phonon Scattering from Measurements on the Doppleron and Gantmakher-Kaner Oscillations in Cadmium.- On the Homomorphic Cluster CPA.- Pseudopotentials and Alloying Behaviour.- Electronic Transport in Intermediate Valence Compounds.- Deviations from Mathiessen's Rule due to Surface Scattering: Aluminium.- Long Wavelength Optical Lattice Vibrations and Structural Phase Transition in Mixed a-In2S3-xSex Crystals.- Electronic Structure and Magnetic Properties of the TiFexCo1-x System.- The Determination of Mg Surface Enrichment in Heat Treated AlMgSi Alloys using the SXES Method.- The Effect of Heat Treatment on the Electron Structure of Dilute AlMgSi Type Alloys.- Electronic Densities of States and Surface Segregation in Alloys.- Metallurgical Effects on Magnetic Properties of the Alloy 15.7 at % Fe-Au.- 2. Dielectric Properties of Metals.- Rotoplasmonic Excitations in the Electron Gas.- Theory of Excited States for Many-Electron Systems by Means of Variational Principles for Subspaces.- Static Electric Field Profile in a Metal and Electroreflectance.- 3. Disordered Systems.- The Fictitious Equilibrium Ensemble in the Theory of Quenched Disordered Systems.- Local Order in Molten Sel-xTex.- Numerical Investigation of the DC-Conductivity and Electron Localisation in One-Dimensional Disordered Systems.- One-Dimensional Disordered Systems with PeriodicBoundary Conditions: Density of States and Shape of Wavefunctions.- Numerical Calculation of Conductivity of Disordered Systems.- Transport Properties of the Blue Bronze K0.30MoO3.- Critical Behaviour near the Conductor-Insulator Transition in Disordered Solids: A Mode-Coupling Theory.- 4. Amorphous Semiconductors.- Classification of Chemical Ordering in Amorphous and Liquid Semiconductors.- Properties of a Model Structure for Hydrogenated Amorphous Silicon.- Comparison of Irradiation Effects in Vitreous Silica Bombarded by Particles of Different Mass and Energy.- EXAFS of Silica and Silicate Glasses.- Dopant Configurations in a-Se and a-Si.- The Electronic Structure of Silicon Nitride.- Investigations of Hydrogenated Amorphous Silicon by High Resolution NMR of 29Si.- 5. Glasses.- Remanent Magnetization of an Insulating Spin Glass: Eu0.4Sr0.6s.- Electrical Resistivities of FexNi80-xB-18Si2 Alloys.- Thermoelectric Power of Amorphous FexNi80-xB-20 Alloys.- 6. Chalcogenides.- Light Absorption and Photocurrent Oscillations in a-GeSe2 Films.- Some Reflections on Energy Gaps in Amorphous As2Se3 and As2S3.- Electrical Properties of Semiconductors in Presence of Potential Fluctuations. I. High Temperature Range.- Electrical Properties of Semiconductors in Presence of Potential Fluctuations. II. High Electric Field Effect and Low Temperature Range.- Electron Relaxation in Eu3-xGdxS4 by Mössbauer Speccroscopy.- Magnetic Properties of Thalium Chromium Chalcogenides.- n~Type Conduction in Chalcogenide Glasses of the Ge-Se-Bi System.- 7. Surfaces and Interfaces.- Direct and Indirect LCAO Recursion Methods for Surfaces.- Core Level Shake up Structures of N~ Adsorbed on Nickel Surfaces: Cluster Models.- Low Energy Ion Scattering Studies of Sodium Segregation in ZnO.- Formation ofSb- and Bi-Clusters in He-Atmosphere.- SERS from Adsorbed Molecules on Metal Surfaces.- Consequences of Density Gradients on Surface Forces of Interfaces.- An Experimental and Theoretical Study of the Electronic Structure of the W (111) Surface.- High Frequency Response and Conduction Mechanism in Thick-Film (Cermet) Resistors.- Gold-Silicon Interface: Electron Energy Loss and Auger Spectroscopies versus Gold Coverage.- Surface and Interface Acoustic Phonons in Aluminium-Coated Silicon.- Optical Excitation of Quadrupole Plasma Oscillations in Ellipsoidal Particles.- 8. Molecular Crystals.- Factor Group Splitting and Multipole Interactions in Molecular Crystals.- Critical Slowing Down of Orientational Fluctuations and Single Molecule Reorientation Rate at an Order Disorder Transition of a Molecular Crystal.- Positron Annihilation Studies of Vacancies and Polyvacancies in Molecular Crystals.- Brillouin Scattering Study of the Phase Transition of Benzil.- Excitation and Radiative Properties of Surface Exciton States in Organic Molecular Crystal: Experimental Evidences and Quantum Mechanical Interpretation.- Author Index.