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International Union of Crystallography
XVII Congress and General Assembly

Seattle Evenings

Evening activities included a historical session '100 years of X·rays' chaired by J. Glusker and A. Beevers. In the middle of his 'Reminiscences of the Early Days' Arnold delighted the audience by breaking into a crystallographic song that he wrote long ago, during an exceptionally dull summer school on direct methods. Other speakers were B. W. Batterman 'On the Discovery of X-rays'. I. Karle 'Crystal Structure Determinations', R. Langridge 'Computing in Crystallography', O. Kennard 'Why have Crystallographic Databases?', and M. G. Rossman on 'Protein Crystallography'. On another evening there were talks associated with the 'Art of Crystallography' exhibition. On the excursion day some went to visit waterfalls and a winery, while others went to the local volcano. Mt Rainier, a spectacular snow covered mountain with many glaciers on its flanks. The opening reception was held on a fine day at the Waterfront Convention Center with a beautiful view of Mt Rainier at sunset over the water. Another evening reception at a 'Science Center' offered many hands-on exhibits and a highly amplified pop band for our entertainment. (Personally I would have preferred a more peaceful string quartet.)

The main course at the Banquet Thursday evening was a unique Northwest specialty, 'Seasame seared Kasu Cod with Candied Ginger Cream'. J. Howard invited everyone at the banquet to come to the IUCr '99 in Glasgow. Then a native Glaswegian, C. Wilson, issued an invitation in his 'mother tongue' (incomprehensible to most), which C. Gilmore translated into standard English. R. Harlow. founder of the 'R. Harlow Foundation for Disabused Crystallographers', donates $100 annually as 'The ORTEP of the Year Award' to anyone who locates the best example of an incorrect structure as determined from its ill-defined thermal ellipsoids. This year the prize was won by V. Young, who re-determined a structure at low temperature and proved that the atoms previously thought to be oxygen were actually hydrogen.

K. Crennell

Session Reports

Time Resolved Micro-Crystal High Energy Applications (01.05): Highlights of the microsymposium included discriptions of the use of diffraction anomalous fine structure (J.-L. Hodeau), a device to give circularly polarized synchrotron radiation of either helicity (J. C. Lang) and a micro-manipulator and scanning electron microscope to mount tiny crystals (R. Neder). J. C. Hanson described how Angle Dispersive Time Resolved Powder Diffraction has allowed Rietveld refinement of the geometrical parameters of acorns in an alumino phosphate structure, so that the time course of thermal dehydration could be followed on video.

M. M. Harding

In the microsymposium on Charge, Spin and Momentum Density (09.01) four speakers described their algorithms and programs for application of the Maximum Entropy Method (MEM) in charge density analysis. Contradictory results concerning the existence of non nuclear attractors in Be, led to a simulating discussion on the need for non uniform prior probability before using MEM routinely in multipolar analysis. An interesting talk on transferability of the electron density parameters to macromolecules suggested that given a data bank of multipolar parameters of atoms, we may soon be able to estimate the electrostatic properties of small proteins.

C. Lecomte

High Tc Superconducting Materiais (10.05). New insights on predictive ability and new materials were the themes of this microsymposium. The keynote speaker Catherine Chaillout (Grenoble) described the need for different techniques to understand the complex structures exhibited by high temperature superconductors. Structural features of high pressure spin-ladder compounds (M. Takano. Kyoto U.), a new class of cuprates closely related to the cuprate superconductors, were described in the context of their novel physics. Presentations on metal oxide metal-pnictide layered compounds (S. Kauzlarich. U. of California-Davis), new layered cuprates with tin and titanium in the blocking layer (K. Poeppelmeier. Northwestern U.) and new superlattice structures (D. Johnson, U. of Oregon) composed of an integral number of intergrown metal dichalcogenide layers. A recurring theme in the presentations was the importance of a comprehensive experimental approach combined with traditional crystallographic methods.

Kenneth R. Poeppelmeier
Banquet attendees: Paul Bajaj, Shih-Lin Chang, Aldo Craievich. Yan Gao, Mingdong Huang, Stephen Hull, Nobuo Ishizawa. Victor Streltsov. Harumi and Takamitsu Yamanaka.

In his Keynote Address The Crystal Packing of Organic Small Molecules (11.00). A. Gavezzoti gave an overview of the methods employed in the analysis of crystal packing including analysis of packing coefficients (the ratio between the molecular volume and the unit cell volume) and the use of principal component analysis to define independent properties and computational models that link structure and thermodynamics. He discussed the calculation of the packing energy for different polymorphic forms using an empirical force field, and the differences between crystal and solution structures. He described the calculation of the carboxylic acid dimer to catemer jump fluctuations in solution by molecular dynamics that lead to an understanding of crystal growth and the prediction of crystal structure.

Sine Larsen

Surface II: Thin Films and Multilayers (12.02) included talks on metal films, semiconductors, oxides, liquid/solid interfaces and scattering theories. Most of the experimental studies used synchrotron radiation and described the structures of multilayer interfaces studied by X-ray scattering. X-ray scattering is used with increasing frequency to investigate interface structures of crystalline and non-crystalline thin layers, without destroying samples and correlated roughness structures in muItilayers relevant to electronic, optical and chemical properties of synthetic multilayers and their growth. New structures and techniques coming onto the scene include quantum dots and speckle techniques.

H. Hashizume

Diffraction Physics

M. Salamon began the Symposium on Magnetic Structures with Neutron and Synchrotron Radiation (15.02) by illustrating the species-sensitivity of resonant X-ray magnetic scattering, and describing the direct observation of the 5d moment induced on non-magnetic Lu atoms when they are dispersed in a magnetic Dy host lattice. A. Goldman demonstrated how the polarization dependence of resonant and nonresonant X-ray cross-sections can be used to deduce the moment-directions of unknown magnetic structures in a variety of rare earth nicklate superconductors. R. Robinson described magnetic crystallographic studies of several uranium intermetal1ics. K. Hirota discussed recent neutron scattering studies of one-D spin-Peierls systems, complemented by high resolution X-ray studies. A highlight of the session was T. Bruecke!'s demonstration of how the increased penetration depth possible with high energy magnetic scattering (50-100 keV) offers a new direction for characterizing magnetic structures, particularly transition element magnetism. Finally, G. Gruebel (ESRF) discussed the use of resonant and nonresonant X-ray scattering for separating the orbital and spin magnetization densities in materials with fascinating new results on rare earth metals.

Doon Gibbs

Crystal Growth

In his Keynote Address, Morphology of Crystals Based on the Theory of Hartman &- Predok, and on tht Roughening Transition (16) P. Bennema gave an enthusiastic and detailed exposition of his theory of Crystal Graphs - connected nets of bonding contacts for every hkl plane, summarizing the crystal-growth behaviour in every direction. The theory is based on Hartman's original concept of Periodic Bond Chains (enhanced by consideration of surface roughening phenomena) and the application of computer analysis. A variety of applications were shown, many of which exhibited pleasing agreement with theory.

J. H. Robertson

In the Macromolecular Crystallization Workshop (16.01), A. McPherson introduced the audience to some of the current approaches to characterizing macromolecular crystal growth, focusing principally on the use of atomic force microscopy to elucidate the mechanisms of protein and virus crystal growth, visualize defects, and observe some unexpected phenomena such as the incorporation of microcrystals into larger, growing crystals, and reviewing current approaches to optimizing protein crystal growth conditions. R. Cudney emphasized the use of data bases for developing new screening approaches to specific problems, and discussed some of the pitfalls associated with the process. G. DeTitta discussed the use of temperature control to promote crystallization, and the design of new apparatus, that allowed the careful screening of conditions over a continuum of temperatures. A. Ducruix used lysozyme as a model system, to illustrate the effects of anions and cations on protein solubility, and suggested how they might be used to control crystal growth. J. Ng described how specific tRNA's could be selectively crystallized for a tRNA mixture by manipulation of conditions. He also presented results from investigations of RNA crystallization using a variety of novel polyamines. A. Edwards closed the session with what was probably the most unique approach to crystallization. By selectively forming abbreviated, yet active domains of a protein, crystals of proteins could be obtained in an expeditious manner using standard techniques.

Alexander McPherson
Banquet attendees: Jörg Ihringer, Caroline and Detlef Klimm, Peter Main, Takeo and Yuriko Matsumoto, Masaaki Ohmasa and Kazuma Ohsumi.

The highlight of the session on Fundamentals of Crystal Growth (16.02) was a molecular dynamic simulation (H. Huitema) of the generation of stacking faults, and healing of these defects, depending on time available and distance to the interface. Rough and smooth interfaces act differently. Screw dislocation dipoles were shown to be competitive with conventional 2D nucleation and dislocations in generation of steps on a growth interface (N. B. Ming). At supersaturation (~20%) used for fast growth of ADP-KDP crystals there is little dependence of vicinal hillock on supersaturation while step rate shows an atypical decrease on ADP. Impurities produce a well pronounced S-shape n(s) dependence of the step rate (n) vs supersaturation(s) and a slight sublinear dependence. Content of Fe, Cr, Al and organic impurities changes the n(s) dependence. A hollow core around the dislocation step source in KDP crystals was revealed by atomic force microscopy (L. N. Rashkovich, DeYoreo). Ga atoms diffuse from the (111) to the (100) face of GaAs during MBE to distances up to 1 micron. The distance depends on the arsenic flux to the surface. This effect changes the temperature of transition between the 2D nucleation and step flow mo4es (T. Nishinaga). A spectral sensitive optical interferometric technique developed by K. Bachmann allows measurement of the growth rate from dense gases, oscillations corresponding to deposition of one atomic layer. Nucleation and spread of epitaxial monolayers of Ge on Si were observed by STM at temperatures up to 900 K and captured on video tape. X-ray topography revealed traditional striations in solution grown KDP crystal and striations due to macrosteps induced by morphological instability (I. L. Smolsky). Periodic roughing and facetting was found, probably due to the variations of impurities (X.-Y. Liu). Transition from folded to unfolded chain crystallization and a corresponding self poisoning effect may be responsible for the existence of an unusual minimum on the dependence of the growth rate on temperature for the ultra-long chain n-alkanes (E. Boda).

A. A. Chernov
 

The most outstanding contribution of the Methods/Materials of Crystal Growth (16.03) session was presented by J. Hulliger, on the growth and characterization of nonlinear-optically (NLO) active organic inclusion compounds. The class of compounds consists of a non-polar molecular host crystal with parallel structural channels into which linearly shaped molecules with acceptor-donor groups can be introduced. Because the inclusion compounds synthesized by the authors are polar (compared with only 25% of the corresponding single-component systems), they can be tailor made for NLO applications. Also in the session K. Kojima reported growth of good quality crystals of C60 and C70 of several millimeters diameter from the vapor phase and the characterization of the fcc C60 crystals by synchrotron radiation topography, etching and microhardness tests. Individual dislocations were observed and dislocation densities, and glide systems determined.

H. Klapper

In the session Controlling and Predicting Crystal Morphology (16.04), F. Leusen described several algorithms for the prediction of crystal habit as a function of solvent, particularly Cerius. J. H. Ter Horst then described the successful application of Cerius to predicting the habits of the explosive RDX, t-Buryrolactone and cyclohexanone. D. Gidalevitz described the use of atomic force microscopy to establish the biomolecular step size of B-acanine and glycine, followed by the use of grazing incidence X-ray diffraction to identify which molecular layers form the step boundaries. I. Kuzmanko correlated of metalloorganic molecular layers and grids with crystal forms, and the development of organically based clays. N. Seeman described a rigid DNA motif that should permit controlled habit control in DNA connected networks.

Ned Suman
Seated (left to right): Aniceta Skowron, Bertram Brockhouse, Doris Brockhouse and I. David Brown, standing (left to right): S. Narasinga Rao, Yu-Sheng Chen, Annegret Haake and Aloysio Janner.

Defects and Microstructure

The session on Characterization of Defects, Microstructure and Texture (17.00) covered a diversity of methods used to reveal order in the 'disorder' of real structures. Three papers showed that conventional texture analysis has a counterpart in an automatic grain orientation evaluation in polycrystalline samples. Real orientation mapping was demonstrated by D. J. Dingley based on backscatter Kikuchi Diffraction patterns. With rather high accuracy (0.01..0.05°) the grain orientation was also calculated from Holz-lines using large angle convergent beam electron diffraction (J. P. Morniroli). A similar accuracy can be achieved with Laue X-ray diffraction in transmission made with a spot size of 20μm diameter (F. Heidelbach). The talk on the polytype transition of SiC (P. Pirouz) could be termed 'order from disorder'. This model explains the formation of domains of different polytype structure by repeated production of stacking faults due to split dislocations. Each single stacking fault is produced by a Frank-Read-like mechanism due to the different velocities of the partial structures demonstrated in electron micrographs. 'Order from disorder' could describe the visually attractive reciprocal space maps measured near Bragg points by means of high resolution X-ray diffraction for samples with quantum wire arrays (L. Tapfer) which perfectly matched the simulations based on a calculated strain distribution. The evaluation of the intensity distribution around Bragg points was also used to investigate 'order in disorder', defects in natural diamond crystals of varying degrees of perfection (K. Lal). A dramatic increase in the perfection of CdZnTe under microgravity conditions acheived in space shuttle experiments was reported by D. J. Larson Jr. Z.W. Hu reported on inversion domains in KTiOPO4 and LiNbO3 in which domains change the structure factor but not the orientation and domain boundary contrast is attributed to stacking faults.

Rolf Koehler

High Pressure Crystallography

In his Keynote Address, Novel Crystal Physics Under Pressure (18) Y. Fuji described advances in maximum pressures, and achieved increased precision at more modest conditions. Although metallization of H2 has been a long-term goal of high pressure science, the required pressure is extremely high. Consequently, Fuji has experimented on molecules of higher molecular weight namely I2, Br2 and IBr. I2 undergoes a series of phase transitions from Cmca to Immm (21 GPa), to I4/mmm (43 GPa), and finally to Fm3m (55 GPa). In the insulator-metallic transition at 21 GPa, molecular form is retained, and intermolecular bonds are formed. To obtain results of higher resolution he studied [N(CH3)4]2, MCl4 (M = Mn, Fe, Zn) phases that have frustrated spin systems that can be described in the Axial Next Nearest Neighbor Ising System. With pressure temperature and Q resolution of 10 Mpa, 0.05°C and 1.2 × 10-4 Å-1, respectively, he has shown that this system demonstrates a series of commensurate phases, not the incommensurate system inferred from lower resolution experiments.

L. W. Finger

Crystal structure analysis under high pressure reveals chemistry of elements and new properties of matter that are often drastically different from those observed at ambient pressure. Some of the most remarkable applications of high pressure crystallography were presented in the microsymposium Elements of Simple Compounds (18.01). N. Hamaya described a pressure-induced phase transition in the crystal of SnI4 at 7 GPa, followed by its amorphisation at 20 GPa. and then its recrystallization into a new metallic phase with the molecules dissociated at 55 GPa. S. P. Besedin reported isotope effects of AlH3 and AlD3 compression, and theoretical predictions of transformations of these analogues into metal. A general review of recent neutron diffraction studies on superionic conductivity in cubic hallides by S. Hull provided new insight into structures of superionic phases. Pressure-induced change of Ga hybridization in rare-earth gallides, investigated both experimentally and theoretically, was vividly presented by U. Schwarz. M. L. Medarde reported insulator-metal phase transitions in perovskites, and explained unusual observations that octahedra tilts decrease with pressure. M. I. McMahon has rewrittten a chapter on the phase diagrams of lanthanides, revising previous results and adding new transformations and phases. Finally, K. Takemura discussed his powder diffraction analysis of Cs, Ba, Zn and Cd, which revealed anomalous compression difficult to reconcile with the absence of phase transitions. Poster communications described other interesting findings. The poster by R. J. Nelmes on new systematics of structural phases of the II-VI, III-V and group IV semiconductors, based on experimental results, is of exceptional importance for technological applications of these materials. The results were reproduced theoretically, as described in the lecture by A. Mujica. Structural systematics of the phases of P, As, Sb and Bi were presented by H. Iwasaki and systematics of groups V, elemental group IV-VI compounds, and the phase transitions in molten and solid KCl and KBr were discussed by S. Urakawa. High pressures are a very efficient means of modifying crystal structures and investigating the properties of matter.

A. Katrusiak

A theme of the microsymposium on Molecules, Ices and Minerals Under Pressure (18.03) was the improvement that has been made in precision of experimental measurements at high pressures, and the range of pressures and temperatures at which such measurements can be made. The majority of oral presentations concerned previously undetected or unsuspected complex phenomena that occur in relatively simple systems: M. S. Somayazula reported the discovery and characterization of a large number of intermediate compounds in the methane-hydrogen systems. High-pressure diffraction studies on H-bonded ices (J. Loveday et al.) including methane and ammonia suggest that structural complexity is a common feature even in mono-molecular solids. High pressure neutron diffraction studies by W. Kuhs of nitrogen and oxygen clathrates (framework structures built of water molecular with guest molecules in cages) show that these also show complex phase transition behavior unsuspected by theoreticians. Relatively simple mineral structures such as cristobalite (SiO2) has also been shown (K. Kingma) to undergo sequences of phase transitions at high pressure while R. J. Angel presented a review of more complex mineral structures that undergo either phase transitions without symmentry change, or changes in compression mechanisms at high presssure. Diffraction techniques at high pressures will continue to reveal a rich variety of previously unsuspected solid state behavior.

Nancy Ross
 
"But why did everyone get child's portions?" Seated (left to right): Kathorine Prince, Jacqueline Vitali, Michael Colaneri and Natalie Colaneri. Standing (left to right) Edward Prince, Elenor Alwyn, Sherry Mowbray, Alwyn Jones, Daniel Mowbray, Vibha Rao, Karl Michel and Evelyn Jabri.

The New Frontiers at High Pressure microsymposium introduced new scientific and technical ideas to high pressure crystallography. Three talks were related to the new instrumentation, three to new sample systems ranging from nanocrystals to biomolecules, and two to new theoretical calculations and graphic displays: I. Goncharenko reported a neutron magnetic scattering study of heavy fermion systems up to 6 GPa in a sapphire anvil cell (SAC) and to 25 GPa in a diamond anvil cell (DAC), and successful observation of systematic magnetic transitions. A pressure-induced antiferro-to-ferromagnetic phase transition of SrFeO3 was clearly observed as a spectral change of hyperfine magnetic field of Fe nucleus monitored with a completely new SR-excited Mossbauer technique up 80 GPa (S. Nasu). A Compton scattering technique with 60 KeV X-rays from a synchrotron source was introduced to survey electronic property under pressure. G. Oomi reported a preliminary result on Li metal in which an appreciable change of the Compton profile is observed at 2 GPa. S. Tolbert carried out both X-ray diffraction and optical absorption on nanocrystals of CdSe, InP and Si ranging 2-50 nm in size and observed systematic elevation of transition pressure due to the nature of quantum confinement. J. Olsen reported an enhanced bulk modulus of Fe2O3 nanocrystal 7 nm in size based on their X-ray diffraction data up to 50 GPa. The pressure effect on biological systems was reported by S. Gruner who observed unusual lattice expansion of the structure of membrane lipid due to an inherent hydration mechanism. The pressure 0.2 GPa is a significantly large purturbation to the biological systems with the carefully balanced competition of interactions. The combination of classical and first principles molecular dynamics can lead to a very powerful procedure in identification of crystal structures. J. Tse predicted a high-pressure structure of several silica systems and a new interactive graphics for systematic crystal chemistry of high pressure silicates was introduced by R. M. Hazen. The pattern of polyhedral linkages is systematically classified and demonstrated.

Y. Fujii

Data Collection and Analysis (18.06), the last session of the high pressure microsymposia, complemented the previous five high pressure microsymposia well. The first three contributions gave the state-of-the-art of image plate high pressure work which attracted many non-high pressure people. The second part showed where the limits of high pressure work are in single crystal, powder and amorphous diffraction. Ample time was given to discussion after each part. J. Parise summarized the whole high pressure event at the end of the session and presented a very tasty "high pressure menu" to both insiders and the curious crowd.

W. F. Kuhs

The microsymposium 25 Years of PDB began with an overview by J. L. Sussman of plans to convert the PDB into a richer 'Three-Dimensional Database of Biological Macromolecules (3DB)', based on an object-oriented approach and a status report on a user friendly deposition procedure, AutoDep, that uses a WWW based interface. E. Meyer described the activity at Brookhaven National Lab leading up to the establishment of the PDB. He stressed that networking and molecular graphics were key components in development. H. Berman discussed the early history of the PDB, and the scientists who played key roles in its establishment. with slides showing how some of them looked in the early '70s and the establishment of the Nucleic Acid Database (NDB). D. R. Davies (NIH) described use of the PDB in research on the immune system allowing determination of new structures via molecular replacement, and facilitation of comparative analyses of these molecules. F. Allen discussed the inter-relationship of the PDB and the Cambridge Structural Database. He showed the parallel increase in the size of the two databases and predicted that by the year 2010, there could be well over 600,000 protein structures in the PDB. G. M. Clore gave a lecture on 'Improving the Quality of NMR and Crystallographic Protein Structures by Means of a Conformational Database Potential Derived from Structure Databases'. He showed the impact that high-resolution X-ray structures were having on developing new conformational potentials for use in NMR structure determination and refinement. It was also very exciting to see that this approach is likely to have an enormous impact in X-ray structure determination; in particular, when only low-resolution X-ray data are available. In such cases the orientations of the side chains are often uncertain. and the new potentials will likely lead to a much better approach than what is used currently. W. Saenger began the final lecture of the microsymposium with a gift of flowers for the occasion. or at least 'virtual flowers' in the form of a beautiful slide, and then went on to discuss what happened to fiber diffraction studies in the PDB. His talk was wonderfully suited to the occasion, and full of humor, focusing on how accurate fiber diffraction studies have had and still have enormous impact on structural biology.

J. L. Sussman
Seated: Sir John Kendrew, Kenneth Holmes, Roberta and Edward Lingafelter. Standing: Julia Mason, Genevieve Le Bas, Stephen Antonysamy, M. Sundaramoorthy.

Teaching Crystallography

In the microsymposium on Teaching Crystallography (23.01) the first three speakers concentrated on crystallographic teaching in various parts of the world. Dr Phavanantha presented a thought provoking talk about Thailand and neighbouring countries. The number of trained crystallographers in relation to the population is small compared to many other countries and the availability of equipment is scarce. The next two speakers demonstrated computer aided instructional materials both for PC and Mac platforms. The last two speakers dealt with the problems of what to include in the crystallographic curriculum at the undergraduate as well as the graduate level for "non-crystallographers" (chemistry, physics, materials science, etc.) which started a very lively discussion in the audience. Seven posters on teaching crystallography were also on display. Two contributions (K. M. Crenell; R. B. Neder and Th. Proffen) displayed instructional materials available on the internet.

Ake Oskarsson

Open Commission Meeting on Charge, Spin and Momentum Density

The meeting was organized to discuss a number of projects of the Commission: Multipole refinement and Maximum Entropy. Thirty to forty people were expected, but the attendance rose to about sixty. The informal character allowed free and extensive discussion. The minutes of the meeting can be obtained from the chairman, K. Schwarz, or the secretary, M. Spackman.

Dirk Feil
"Bring on the Haggis!" Michael Burnett, Jonathan Hanson, Mildred and Lyle Jensen, Fumikuki Marumo. Hitoshi Ohsato, Joseph Pluth, Vurica Srajer, Katsumi Suda and Tsu-Yi Teng.

Open Commission Meeting on International Tables for Crystallography

The editors of the three published (A, B, C) and the four proposed (D, E, A1, A2) volumes of International Tables reported on the present status and the future plans of their volumes. Th. Hahn demonstrated two new features of the Fourth Edition (1995) of Vol. A, "Space-Group Symmetry": completion of the space-group diagram project for all 17 plane and 230 space groups, and introduction of the "double glide plane" e by means of new graphical symbols for 17 space-group diagrams and modifications of five orthorhombic space-group symbols. The plans for the Second Edition of Vol. B, "Reciprocal Space", were presented by the editor U. Shmueli. In addition to minor corrections and major revisions of several existing chapters the Second Edition will contain five new contributions on the following topics: 1. Space-group representations in reciprocal space. 2. Direct methods in electron crystallography. 3. Diffraction by polymers. 4. Reciprocal-space images of aperiodic crystals. 5. Dynamical theory of neutron diffraction. This edition is scheduled for publication in 1997. The editor of Vol. C, "Mathematical, Physical and Chemical Tables", E. Prince, explained that the preparations for the Second Edition of this Volume (to be published in 1997) were about 85% complete at the time of death of the previous editor, A. J. C. Wilson. The rest is presently being edited. Due to rapid obsolescence of much of the tabular material in this volume, an electronic version of Vol. C is presently under active consideration. The new Vol. D, "Physical Properties of Crystals" (1997), was introduced by its editor A. Authier. It consists of three parts: Part 1 treats Tensorial Aspects of Physical Properties; it contains both the general mathematical background and the individual physical properties. Part 2 is devoted to the Symmetry Aspects of Excitations (phonons, electrons, Raman scattering, Brillouin scattering). Part 3 is devoted to the Symmetry Aspects of Structural Phase Transitions, Twinning and Domain Structures. Relevant tables will be included in an accompanying diskette or CD ROM. The new Vol. E, "Subperiodic Groups", is edited by V. Kopsky and D. B. Litvin (1997). The volume is devoted mainly to layer and rod groups, i.e. to groups in three dimensions with lattices of only two or one dimensions. The volume consists of two parts: Part 1: Subperiodic group tables: Frieze, Rod and Layer Groups. Part 2: Scanning of space groups, i.e. layer groups as subgroups of space groups. Vol. A1, "Maximal Subgroups of Space and Plane Groups", was introduced by its editor H. Wondratschek. It is a companion volume to Vol. A, containing the maximal subgroups of space and plane groups. Maximal subgroups of indices 2, 3 and 4 will be listed individually. The infinitely many maximal isomorphic subgroups will be presented by series with the index as parameter. Conjugacy relations will be indicated. The final project ' of the session was presented by T. Janssen. Vol. A2, "N-Dimensional Crystallography" consists of a computer program (CD-ROM) and an accompanying printed volume with a manual and a treatment of the theory of symmetry in arbitrary dimension. This implies that it gives the information on two- and three-dimensional point groups as well. For more than three dimensions, these groups are used already by crystallographers dealing with incommensurate phases and quasicrystals. From a data base are calculated the space groups, the symmetry elements, the Wyckoff positions, the general and special extinction rules, in short all that can be found in the existing tables for 2 and 3 dimensions.