Special report

Crystallography in Australia and New Zealand

Collated and edited by Jennifer L Martin

[Map]The beginnings of crystallography in the region can be traced back to the turn of the 20th century when Sir William H Bragg was appointed Professor of Mathematics & Physics at the University of Adelaide, a post he held from 1886 to 1908. There he experimented with ionizing radiation, which had then only recently been discovered by Roëntgen in Germany. WH Bragg’s son, William Lawrence Bragg, was born and educated in Adelaide and the two Braggs - who moved to the UK in 1908 - were awarded a unique father-and-son Nobel prize in 1915 for “their services in the analysis of crystal structure by means of X-rays”. Another well-known pioneer of crystallography, Lindo Patterson, of Patterson function fame, was born in Nelson, New Zealand, in 1902. His family moved to Canada when he was 18 months old, and later to London when he was 14. Equally famous is Maurice Wilkins, who shared the 1962 Nobel Prize with Watson and Crick “for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material”. He was born in the small town of Pongaroa, New Zealand, in 1916 and moved with his family to England when he was seven.

Crystallography in New Zealand and Australia has blossomed during the last century, reflecting the lasting influence of a small group of outstanding researchers in the early days who, in Australia, referred to themselves as ‘the Bush Crystallographers’. Their legacy is a vibrant and growing research community representing all aspects of the field. Major research groups are based at universities, medical research institutes, the Australian Government Commonwealth Scientific and Industry Research Organisation (CSIRO), the Australian Nuclear Science and Technology Organisation (ANSTO) and the New Zealand Government Crown Research Institutes.

Synchrotron activities

The Australian Synchrotron Research Program (ASRP)

[Morton]PhD student Jonathon Morton (Curtin University), using the ASRP diffractometer in its Debye-Scherrer configuration
In response to the recommendations of reports to the Australian Government from the Australian Science and Technology Council and the National Committee for Crystallography of the Australian Academy of Science, a consortium of government agencies and universities was formed in 1990 to fund the construction of the Australian National Beamline Facility at the Photon Factory in Tsukuba, Japan. This beamline, opened in 1993, gave Australian scientists guaranteed access to overseas synchrotron research facilities for the first time, and catalysed a rapid growth in the Australian synchrotron user community.

A further expansion occurred in 1996, with the formation of the Australian Synchrotron Research Program (ASRP) which added access to six sectors of the Advanced Photon Source (APS) in the USA. The ASRP now supervises and facilitates Australia’s off-shore synchrotron activities, including the employment of Australian beamline scientists, the peer-review of proposals, and the promotion of an extensive post-doctoral research fellowship scheme. Access to the National Synchrotron Radiation Research Centre, in Hsinchu Taiwan, was added to the ASRP programs in 2003.

ASRP at the Photon Factory, Japan

The Australian National Beamline Facility (ANBF) is a general purpose hard X-ray beamline at the Photon Factory. It is equipped for X-ray absorption spectroscopy, high-resolution high-speed powder diffraction, solid surface grazing incidence diffraction, small angle scattering, and X-ray imaging and fluorescence. Two resident ASRP beamline scientists provide expert assistance in the operation, maintenance and development of the facility. The diffraction and scattering experiments are performed in a large vacuum diffractometer combining a Debye-Scherrer geometry with image-plate detectors. This unique instrument was constructed in Australia and can record high resolution powder patterns in 5-10 minutes.

ASRP at the Advanced Photon Source, USA

ASRP subscribes to three beamline groups at the Advanced Photon Source at the Argonne National Laboratory in the USA; X-ray Operations Research, BioCARS and ChemMatCARS. ASRP beamline staff are stationed at all three. This arrangement gives Australian researchers access to six sectors at the APS with facilities for X-ray physics, X-ray microscopy, X-ray fluorescence mapping, micro-XANES, polarization studies, macromolecular structure analysis, static and dynamic condensed-matter chemistry, small and wide-angle X-ray scattering, micro-crystallography, reflectrometry and time-resolved laser-excited single-crystal diffraction.

ASRP at the National Synchrotron Radiation Research Center, Taiwan

This 1.5 GeV synchrotron light source in the Hsinchu Science-Based Industrial Park, Taiwan, provides access for Australian scientific and industrial research in the vacuum ultra-violet and soft X-ray spectral regions. Applications include photoemission and near-edge X-ray absorption spectroscopy, micro-machining (deep X-ray lithography), infra-red microscopy, scanning photoemission microprobe measurements, and photoemission microscopy.

The Australian synchrotron, Melbourne

[Australian synchrotron] Photo courtesy of the Australian Synchrotron. Photographer Daniel Mendelbaum
An Australian Synchrotron light source (pictured) is currently being constructed adjacent to Monash University in Melbourne. It will be a 3-GeV third-generation source with a circumference of 216 m, 12 usable straight sections and the potential for over 30 beamlines. Commissioning first light of the ring is scheduled for April in the first quarter of 2007 when 4 of the initial 9 beamlines are planned to begin operations.

The first 4 beamlines will serve macromolecular crystallography (MAD bending magnet), powder diffraction (bending magnet), X-ray absorption spectroscopy (wiggler), and soft X-ray spectroscopy (helical undulator). The next 5 beamlines will be for macromolecular micro-crystal and small-molecule diffraction, SAXS/WAXS, infra-red spectroscopy, micro-spectroscopy and imaging/medical therapy. For more information see www.synchrotron.vic.gov.au

A new Australian neutron source

[OPAL] OPAL, photo courtesy of ANSTO
In its day, the 1950s HIFAR reactor near Sydney provided state-of-the-art facilities for neutron diffraction. This reactor has now been de-commissioned. Its place will be taken by OPAL, the Australian replacement research reactor, which is due to begin operating in August 2006. A large liquid-deuterium cold neutron source and super-mirror guides will feed into a modern guide hall, in which most of the planned 18 instruments will be placed. Notable features will include a commercial radiography/tomography station and facilities for the neutron irradiation of radio-pharmaceuticals, transmutation-doped silicon and activation analysis samples. The initial instruments will provide facilities for both high-intensity and high-resolution powder diffraction, residual-stress measurements, quasi-Laue diffraction, thermal 3-axis spectroscopy, polarization analysis, small-angle neutron spectroscopy and time-of-flight reflectometry. For more information see www.ansto.gov.au/opal/.

Chemical crystallography

Small-molecule X-ray crystal structure analysis has been an important component of research in university chemistry departments and government agencies in Australia and New Zealand since the early 1950’s, a large number of groups being established during that time and subsequently. [1-18] The first group to be recognized internationally was located at the CSIRO Division of Chemical Physics near Melbourne. Its leaders were A. McL. (“Sandy”) Mathieson, Barrie Dawson and David Wadsley. A remarkably collegiate group, they generously shared their expertise and instruments with younger researchers starting work in the universities.

At the outset, research tended to be focussed on the protagonists’ own interests, but, with the growing recognition of the capabilities, as well as the cost, of the technique, and the constraints of obtaining funding, most groups broadened their activities to provide a service to a wide range of investigators in the chemical and materials sciences. The field burgeoned during the 1960’s when computer-controlled diffractometer installations supplanted Weissenberg and precession camera X-ray facilities and the use of computers became widespread. As elsewhere, the technique became an important ingredient in the characterization and identification of crystalline substances across the chemical, materials, natural product and mineralogical sciences, and many antipodean practitioners feature with distinction in the various data-base compilations. The published work includes very small organic molecules (typical of the 1950’s, when hand calculators restricted calculations to projections down short axes), simple transition metal salts and hydrates, leading into more complex ones (as coordination chemistry gained popularity in the 1960’s and computers enabled three-dimensional calculations), broad front attacks on chemical problems through many chemically related structures (as computing became more straightforward and data acquisition more automated throughout the 1970’s) to the very much larger molecules containing hundreds of atoms. Rationales for these analyses range widely from bio- and pharmacological, to underpinning the understanding of physical effects such as magnetism and electrical properties, and to the understanding of chemical reaction paths, as well as an appreciation of the symmetry and elegance of these structures and processes, to solving structures for more fundamental reasons associated with theoretical and computational development.

With the advent of powerful CCD instrumentation, increasing access to synchrotron facilities in the 1990’s, increasing costs, and increasing competition for research funds, the proliferation of facilities has decreased. Major facilities serve the institutions in a large area and neutron studies will be concentrated at OPAL and there is anticipated access to the Australian Synchrotron (see above).

References

[1] Queensland, Les Power (James Cook Univ.), Colin Kennard (Univ. of Queensland), Peter Healy and Graham Smith (Griffith Univ.)
[2] New South Wales, Hans Freeman (Univ. of Sydney), Neville Stephenson (Univ. of New South Wales), ‘Blue’ Barclay (Macquarie Univ.)
[3] Australian Capital Territory, Glen Robertson (Australian National Univ.)
[4] Victoria, David Wadsley and ‘Sandy’ Mathieson (CSIRO, Vic), John (CB) White and Bernard Hoskins (Melbourne U), Bryan Gatehouse (Monash Univ.) and Maureen Mackay (La Trobe Univ.)
[5] South Australia, Harry Medlin, Mike Snow (Adelaide Univ.), Max Taylor (Flinders Univ.) and Ted Radoslovich (CSIRO, Adelaide).
[6] Univ. of Western Australia, Ted Maslen, ‘Judge’ Bevan and Brian Figgis
[7] Univ. of Auckland NZ (F.J. Llewellyn, David Hall, and Neil and Joyce Waters)
[8] Massey Univ. NZ (Sylvia Rumball)
[9] Univ. of Canterbury NZ (Bruce Penfold and Ward Robinson)
[10] Chemistry Division, Department of Scientific and Industrial Research NZ (Peter Williams, Kevin Brown & Graeme Gainsford)
[11] James Cook Univ., Queensland (sharon.ness@jcu.edu.au)
[12] Sydney Univ., New South Wales (p.turner@chem.usyd.edu.au)
[13] Australian National Univ., Canberra (Rae@RSC.anu.edu.au)
[14] Melbourne Univ., Victoria (j.white@chemistry.unimelb.edu.au)
[15] Monash Univ., Victoria (stuart.batten@sci.monash.edu.au))
[16] Univ. of Western Australia (bws@crystal.uwa.edu.au)
[17] University of Auckland NZ (g.clark@auckland.ac.nz)
[18] University of Canterbury NZ (ward.robinson@canterbury.ac.nz)

Precision density studies

Charge density research is actively conducted in two locations: the University of Sydney and the University of Western Australia. For the past few years, the group in Sydney [1] has used the Crystal Structure Analysis Facility of the School of Chemistry, and the HIFAR research reactor, to gain insight into drug-related organic molecules through X-ray and neutron diffraction studies. A group, which at the University of New England in Armidale conducted model studies analyzing the possibilities for determining molecular properties from X-ray diffraction data, has recently moved to the University of Western Australia [2] where their research will focus on extracting information on nonlinear optical properties from X-ray diffraction data, through a series of combined experimental and theoretical [3] studies. The experimental work will make use of single crystal X-ray diffraction facilities in Perth and Sydney, and new instruments at the OPAL reactor in collaboration with ANSTO [4].

Charge density research is now a major activity of worldwide modern crystallography, but its development was fostered by pioneering studies in Australia. These included early work on the multipole refinement model by Barrie Dawson in Melbourne in the 1960s, detailed charge density studies on materials ranging from organics to rare earth oxides and low-T superconductors by Ted Maslen and co-workers at the University of Western Australia, and combined X-ray and polarized-neutron charge and spin density studies on transition metal complexes by Brian Figgis and colleagues using a 10 K diffractometer, also at the University of Western Australia, in the 1990s.

References

[1] University of Sydney, New South Wales, Dai Hibbs d.hibbs@chem.usyd.edu.au
[2] University of Western Australia, Mark Spackman mas@cyllene.uwa.edu.au
[3] University of Western Australia, Dylan Jayatilaka dylan@theochem.uwa.edu.au
[4] ANSTO New South Wales, Wim Klooster wim.klooster@ansto.gov.au

Fibre diffraction

[Frog muscle micrograph](Top) Small section of frog muscle micrograph and (Bottom) classification of myosin filament orientations.
Fibre diffraction analysis is concerned with obtaining detailed structural information from fibrous specimens: specimens that are oriented and rotationally disordered. The molecules usually have helical symmetry and the rotational disordering leads to cylindrical averaging of the X-ray diffraction intensities in reciprocal space. The challenge is to determine structures from this limited data.

Fibre diffraction has a significant history in Australia, dating back to cutting-edge research by Bruce Fraser and Tom MacRae in the 1950s in Melbourne [1]. In the context of a large laboratory serving the Australian wool industry, this work produced important structural results on collagen and keratin. An early collaborator on this work continues research on fibrous proteins in New Zealand [2].

A group at the University of Canterbury [3] uses fibre diffraction together with the theory of diffraction by disordered lattices to study systems that are both rotationally disordered and subject to various forms of lattice or substitution disorder within the constituent microcrystallites. Diffraction from these specimens consists of Bragg diffraction with amplitudes that are modulated by the disorder and diffuse diffraction between the reciprocal lattice points. Such problems arise in a variety of contexts including artificially prepared fibre specimens, such as nucleic acids and polysaccharides, and naturally occurring assemblies such as in vertebrate muscle. A current collaborative project [3, 4], analyses the rotational disorder of myosin filaments in myofibrils of higher vertebrate muscles, which is critical for the rigorous application of fibre diffraction analysis to muscle. Electron microscopy allows direct observation of the disorder and current efforts are aimed at modelling the disorder and developing a description of the diffraction.

Other activity in fibre diffraction and disordered materials includes studies of cellulose microfibril orientation in wood [5], use of reflection high-energy electron diffraction to study crystal orientation and growth in compound semiconductor thin films [6], and a variety of industrial applications to cement, fertilisers and soils.

References

[1] Wool Textile Research Laboratory, CSIRO, Victoria. Bruce Fraser and Tom MacRae
[2] Massey University, NZ, David Parry (d.parry@massey.ac.nz)
[3] University of Canterbury, NZ Rick Millane (rick@elec.canterbury.ac.nz)
[4] Imperial College, UK, John Squire (j.squire@ic.ac.uk)
[5] University of Canterbury, NZ, Ward Robinson (ward.robinson@canterbury.ac.nz)
[6] University of Canterbury, NZ, Steve Durbin, (s.durbin@elec.canterbury.ac.nz)

X-ray phase-contrast imaging and microscopy

Phase-contrast X-ray imaging exploits the phenomenon of Fresnel diffraction. By comparison with conventional absorption type X-radiography, it includes an additional contrast mechanism in image formation that arises from the effects of refraction by the sample. This provides complementary information and is of particular value for weakly- and/or non-absorbing samples.

Early work at CSIRO [1] into the development of methods for phase-contrast imaging was based around a “double crystal” technique (now called Diffraction Enhanced Imaging - DEI). However, this had practical limitations and a more practical and robust method was developed that did not rely on optics and could use broadband polychromatic radiation from a conventional microfocus source. This method, termed In-Line phase contrast imaging, is now widely used in many conventional laboratories. It was developed independently [1] of a related synchrotron-based approach outlined elaborated by Anatoly Snigirev and co-workers at the ESRF. CSIRO [1] also developed a very high spatial resolution X-ray ultramicroscope (XuM) which used an SEM as host and exploited phase contrast. This instrument has achieved sub-100 nm resolution (on semiconductors) and provides very high spatial resolution tomography. Examples of processed XuM images recorded on this instrument are presented below.

[3 diagrams]
Pioneering research into the development of theoretical methods for extracting quantitative information from phase-contrast images has been carried out at the University of Melbourne [2]. This involved the development of phase-retrieval algorithms with application to visible light optics, X-rays, neutrons and particle beams. A collaboration between CSIRO [3] and Monash University [4] investigates multienergy and polychromatic approaches to phase retrieval as well as hybrid approaches combining DEI and in-line imaging. A unified conceptual framework for the whole multiplicity of phase-contrast imaging techniques is provided by the idea of virtual (software based) optics that has been developed both at Melbourne University [2] and more recently, for the specific case of X-ray phase-contrast imaging, by CSIRO/Monash [3,4].

Researchers at Monash University [5] have a particular emphasis on biomedical applications of DEI (which enables images based on absorption or refraction to be separately obtained and also removes parasitic scattering). Conventional laboratory based applications of phase-contrast imaging to biomedical studies have also been extensively carried out at CSIRO [6].

Several of these groups [1,2,5,6] are collaborating on the design of a unique imaging beamline for the Australian synchrotron. This is intended to facilitate a wide range of applications and aims to provide optimized implementations of In-Line phase contrast imaging as well as DEI.

References

[1] CSIRO Victoria, Steve Wilkins (Steve.Wilkins@csiro.au)
[2] Melbourne University, Victoria, Keith Nugent, k.nugent@physics.unimelb.edu.au)
[3] CSIRO Victoria, Tim Gureyev (tim.gureyev@csiro.au)
[4] Monash University, Victoria, David Paganin (david.paganin@spme.monash.edu.au) and Konstantin Pavlov (konstantin.Pavlov@spme.monash.edu.au)
[5] Monash University, Victoria, Rob Lewis (Rob.Lewis@sync.monash.edu.au)
[6] CSIRO, Victoria, Andrew Stevenson (Andrew.Stevenson@csiro.au)

X-ray Absorption Spectroscopy (XAS)

XAS was pioneered in Australia by Hans Freeman [1] in the early 1980s. His XAS experiments were designed as a complement to crystal structure analysis of metalloproteins and included the first XAS studies of oriented metalloprotein crystals. A by-product of this work was the XFIT software for single- and multiple-scattering fits to XAFS data. The software is still in use today. XAS studies expanded rapidly in the mid 1990s after the ASRP was established and it has since grown at a rapid rate.

The largest concentration of XAS users is at the University of Sydney, covering areas as diverse as structures of the active sites of metalloproteins, intracellular XAS for studying biotransformations of toxins and drugs, characterization of drugs, coordination complexes, homogeneous and heterogeneous catalysts, network materials, etc [2,3]. At the Australian National University (ANU) [4], research is conducted into the structures around metal ions in minerals and melts of relevance to the formation of minerals. Studies in this area are also conducted by groups at ANSTO [5] and CSIRO [6]. In the semiconductor area there is extensive research expertise at ANU [7]. The University of New South Wales is the centre of the soft X-ray XAS community in Australia [8] where semiconductors are also a major research theme along with studies on other materials. Spectroelectrochemical XAS experiments are performed by research groups at the Universities of Sydney [2] and Melbourne [9] and the ANU [10]. The University of South Australia [11] applies XAS techniques to problems in mineral processing, forensic chemistry and industrial materials. Groups at the University of Queensland [12] conduct a variety of studies on surfaces, coordination complexes and metalloproteins.

In New Zealand, XAS activity has been concentrated at the University of Auckland, the Victoria University of Wellington, and two Crown Research Institutes, Industrial Research Ltd. and Geological and Nuclear Sciences. Major applications have been in the areas of semiconductor thin films, [13] Lithium Ion Battery cathode materials [14,15] and High Tc Superconductors [16]. Recently, emphasis has shifted increasingly to soft X-ray XANES, with speciation studies on electrode impurities [15] and studies of semiconductor materials [15,17,18]. The earliest XAS studies by New Zealand researchers utilized the LURE facility in France, while more recent XANES work has used the SRC in Madison, Wisconsin and the NSRC in Taiwan.

Through the ASRP, Australian researchers have access to worldclass XAS instrumentation: ANBF operates a dedicated bending magnet beamline at the Photon Factory, Micro-XAS on biological tissues and materials can be performed on the XOR sector at the APS and at the NSRRC in Taiwan the main XAS focus is on soft X-rays. The first suite of nine beamlines for the Australian Synchrotron will include a dedicated XAS beamline and a microprobe XAS beamline.

References

[1] University of Sydney, New South Wales, Hans Freeman (freemanh@chem.usyd.edu.au)
[2] University of Sydney, New South Wales, Peter Lay (p.lay@chem.usyd.edu.au)
[3] University of Sydney, New South Wales, Trevor Hambley (t.hambley@chem.usyd.edu.au), Tony Masters (a.masters@chem.usyd.edu.au), Thomas Maschmeyer (t.maschmeyer@chem.usyd.edu.au), Cameron Kepert (c.kepert@chem.usyd.edu.au), Hugh Harris (h.harris@chem.usyd.edu.au), and Marjorie Valix (mvalix@chem.eng.usyd.edu.au)
[4] Australian National University, Canberra, Andrew Berry, (Andrew.Berry@anu.edu.au)
[5] ANSTO Victor Luca (vlu@ansto.gov.au) and Anton Stampfl (aps@ansto.gov.au)
[6] CSIRO - Land and Water, Enzo Lombi, (Enzo.Lombi@csiro.au), Exploration and Mining, Barbara Etschmann, (Barbara.Etschmann@csiro.au), and Health Sciences & Nutrition, Victor Streltsov (victor.streltsov@csiro.au)
[7] Australian National University, Canberra, Mark Ridgway (Mark.Ridgway@anu.edu.au)
[8] University of New South Wales, New South Wales, Rob Lamb (r.lamb@unsw.edu.au) and Alan Buckley (a.buckley@unsw.edu.au)
[9] University of Melbourne, Victoria, Stephen Best (spbest@unimelb.edu.au)
[10] Australian National University, Canberra, Graham Heath (graham.heath@anu.edu.au)
[11] University of South Australia, South Australia, Andrea Gerson (Andrea.Gerson@unisa.edu.au) and Ivan Kempson, (Ivan.kempson@unisa.edu.au)
[12] University of Queensland, Mark Riley (m.riley@uq.edu.au) and Ian Gentle (i.gentle@uq.edu.au)
[13] Victoria University of Wellington, NZ Joe Trodahl (Joe.Trodahl@vuw.ac.nz)
[14] Pacific Lithium Ltd, NZ, Brett Ammundsen (brett@pacifi clithium.co.nz)
[15] University of Auckland, NZ, Jim Metson (j.metson@auckland.ac.nz)
[16] Industrial Research Ltd. NZ, Jeff Tallon j.tallon@irl.cri.nz
[17] Victoria University of Wellington, NZ Ben Ruck (Ben.Ruck@vuw.ac.nz)
[18] Institute of Geological and Nuclear Sciences. NZ, Andreas Markwitz (a.markwitz@gns.cri.nz)

Biocrystallography

[Actinidin and SpeB]Two unlikely evolutionary neighbours: the kiwifruit enzyme actinidin (left), solved in 1977, and the bacterial “flesh-eating” protease SpeB (right), solved 23 years later
Protein crystallography in Australia and New Zealand has developed rapidly over the past thirty years. In New Zealand, there are structural biology research centres at three Universities. The first was established by Ted Baker [1] (a recent IUCr President) at Massey University in Palmerston North. An early milestone from this group was the structure determination in 1977 of the cysteine protease actinidin and later work on the iron binding protein lactoferrin attracted significant US funding that fully established the laboratory. The Baker lab moved from Massey to the University of Auckland in 1997, where it has grown to encompass several other groups [2] and more than 40 researchers. The lab is now part of one of New Zealand’s national Centres of Research Excellence. Its research focus is on structural genomics, particularly of TB proteins, structure-based drug design, viral crystallography and protein engineering. At Massey University there are four research groups [3,4] working on metalloproteins and enzymes, particularly those of importance in the dairy industry. There is emphasis [3] on twinning, ultra-high resolution structures and solving “difficult” crystal structures. The third centre, and arguably the southernmost crystallography laboratory in the world, is based at Otago University in Dunedin [5] where “wet” biochemistry and crystallography are combined in investigations of enzyme structure and mechanism.

[Influenza]The original beta-propeller: Crystal structure of subunit of influenza virus neuraminidase with product, sialic acid.
In Australia, structural biology research centres are based in the major cities of Sydney, Melbourne, Brisbane, Canberra and Adelaide. The first laboratory was established by Hans Freeman [6] at the University of Sydney in the early 1970s, specialising in the structures of metalloproteins. The structure of the copper protein, plastocyanin, was determined in 1977, and (in collaboration with colleagues at the Stanford Synchrotron Radiation Laboratory) the first MAD analysis of a metalloprotein structure, using the intrinsic metal atom as the anomalous scatterer, was reported in 1988. The laboratory moved from the School of Chemistry to the Dept. of Biochemistry of the University in 1994, with Mitchell Guss [7], a long-time colleague of Hans Freeman (and currently co-editor of Acta Cryst. D and joint editor of Acta Cryst. F) as director. Metalloprotein structures continue to be a major theme of the research. Several other groups have been established at Sydney with interests in antibiotic resistance and DNA-drug interactions. [8]

Peter Colman established a protein crystallography group at CSIRO in Melbourne in 1978. Five years later his team [9,10] determined the structure of neuraminidase, one of the two major coat proteins of the influenza virus. The structure, reported to be the first to be solved by cross-crystal electron density averaging, led to the development of the anti-flu drug Relenza™, one of the earliest examples of successful structure-based drug design.

Peter Colman now heads a structural biology department at one of Australia’s foremost medical research institutes, the Walter and Eliza Hall Institute (WEHI) [9]. There, his research focuses on viral proteins and proteins involved in cancer. Other groups at WEHI pursue structural studies of hormone receptors such as those for insulin-like growth factor and epidermal growth factor [11] and membrane proteins including ion channels and mitochondrial proteins [12]. Research groups at CSIRO [10, 13] work on the structural biology of receptors and viral proteins.

At the same time that Peter Colman was establishing his laboratory in Melbourne, Neil Isaacs founded a protein crystallography unit at the St. Vincent’s Institute of Medical Research also in Melbourne. In Dec 1988, Neil left Australia to take up the Chair of Protein Crystallography at the University of Glasgow in Scotland. The St Vincent’s unit was re-established by Michael Parker in 1991 [14] with research on pore-forming toxins, glutathione transferases and protein kinases. The unit’s current structural interests are relevant to problems in neurobiology, cancer and infection.

In the early nineties there was rapid growth in biocrystallography in Australia, with new laboratories in Canberra, Sydney and Brisbane. In Canberra, a group was set up at the Australian National University [15] with research interests in protein engineering and more recently in receptors. At the University of New South Wales in Sydney, protein crystallography was developed in the School of Physics [16], with recent research into cold adaptation proteins and proteins that function both in water-soluble and chloride channel forms. Queensland’s first protein crystallography laboratory was at the University of Queensland [17] with a focus on structure-based drug design, protein folding and more recently high throughput crystallography applied to macrophages [17,18]. In addition, the University of Queensland now has two other structural biology groups studying protein kinases, protein-protein interactions, nuclear import proteins [18] and a variety of enzyme drug targets [19].

The rapid expansion of protein crystallography in Australia in the early 1990s has been repeated in this century. There are new groups in Melbourne [20,21,22], Queensland [23], Canberra [24] and South Australia [25,26]. From small beginnings in the 1970s, the protein crystallography community in Australia and New Zealand has grown to over thirty groups. It is expected that the completion of the first phase of the construction of the Australian synchrotron in Melbourne in 2007, with two proposed PX beamlines, will attract even more structural biologists to the region. The growth and development of the field make this an exciting time for structural biologists ‘down under’.

References

[1] University of Auckland, NZ, Ted Baker (ted.baker@auckland.ac.nz)
[2] University of Auckland, NZ, Peter Metcalf (peter.metcalf@auckland.ac.nz), Vic Arcus (v.arcus@auckland.ac.nz), Sean Lott (s.lott@auckland.ac.nz), Richard Kingston (rl.kingston@auckland.ac.nz)
[3] Massey University, NZ, Geoff Jameson (g.b.jameson@massey.ac.nz)
[4] Massey University, NZ, Gillian Norris (g.norris@massey.ac.nz), Bryan Anderson (b.f.anderson@massey.ac.nz), Andrew Sutherland-Smith (a.j.sutherland-smith@massey.ac.nz)
[5] Otago University, NZ, John Cutfield (john.cutfi eld@stonebow.otago.ac.nz) and Sue Cutfield (suemc@sanger.otago.ac.nz)
[6] University of Sydney, New South Wales, Hans Freeman (freemanh@chem.usyd.edu.au)
[7] University of Sydney, New South Wales, Mitchell Guss (m.guss@mmb.usyd.edu.au)
[8] University of Sydney, New South Wales, Charles Collyer (c.collier@mmb.usyd.edu.au), Adrienne Adams (a.adams@mmb.usyd.edu.au)
[9] Walter and Eliza Hall Institute, Victoria, Peter Colman (pcolman@wehi.edu.au)
[10] CSIRO Health Sciences and Nutrition, Victoria, Jose Varghese (Jose.Varghese@csiro.au)
[11] Walter and Eliza Hall Institute, Victoria, Tom Garrett (tgarrett@wehi.edu.au)
[12] Walter and Eliza Hall Institute, Victoria, Jacqui Gulbis (jgulbis@wehi.edu.au)
[13] CSIRO Health Sciences and Nutrition, Victoria, Mike Lawrence (mike.lawrence@csiro.au)
[14] St Vincents Institute of Medical Research, Victoria, Michael Parker (mparker@svi.edu.au)
[15] Australian National University, Canberra, David Ollis (ollis@rsc.anu.edu.au) and Paul Carr (carr@rsc.anu.edu.au)
[16] University of New South Wales, Paul Curmi (p.curmi@unsw.edu.au)
[17] University of Queensland, Jennifer Martin (j.martin@imb.uq.edu.au)
[18] University of Queensland, Bostjan Kobe (kobe@uq.edu.au)
[19] University of Queensland, Luke Guddat (guddat@mailbox.uq.edu.au)
[20] Monash University, Victoria, Jamie Rossjohn (jamie.rossjohn@med.monash.edu.au), Matthew Wilce (matthew.wilce@med.monash.edu.au), Ossama El-Kabbani (el-kabbani@vcp.monash.edu.au)
[21] St Vincents Institute of Medical Research, Victoria, Galina Polekhina (gpolekhina@svi.edu.au)
[22] Austin Research Institute, Victoria, Paul Ramsland (p.ramsland@ari.unimelb.edu.au)
[23] Griffith University, Queensland, Helen Blanchard (h.blanchard@griffith.edu.au)
[24] Australian National University, Canberra, Aaron Oakley (oakley@rsc.anu.edu.au)
[25] Flinders University, South Australia, Ian Menz (ian.menz@fl inders.edu.au)
[26] University of Adelaide, South Australia, Maria Hrmova (maria.hrmova@adelaide.edu.au)

Powder diffraction

Powder diffraction research has been heavily influenced by the availability of facilities at the Australian “HIFAR” reactor and, over the past decade, by access to the Debye Scherrer diffractometer at the Photon Factory in Japan. Extensive use is also made of major facilities in Europe and the USA.

Many crystallographers at the School of Chemistry, University of Sydney, routinely use powder diffraction methods. A major collaborative effort with ANSTO, looking at the fundamentals of structural phase transitions in perovskite based oxides, has focused on combining parametric studies, very high resolution neutron and synchrotron X-ray diffraction and group theory to understand the nature of the observed crystallographic phase transitions [1]. A second group at Sydney [2] uses PXRD to monitor the structural consequences of desorption and sorption of guest molecules from nanoporous molecular hosts. Studies of the thermal expansion properties of molecular frameworks has seen the discovery of a broad family of negative thermal expansion (NTE) materials. Others study phase-separation in ‘electron-doped’ colossal magnetoresistive (CMR) manganite perovskites [3] using the complementary techniques of synchrotron X-ray and neutron powder diffraction, as well as small-angle neutron scattering and polarised neutron scattering. A fourth group at Sydney in the School of Chemistry [4] analyses modulated structures by PXRD. When bismuth oxide is doped with transition metals such as niobium or tungsten, its high-temperature cubic polymorph can be stabilised to room temperature. These doped phases are of interest because they preserve the high ionic conductivity of the cubic form and are being studied through a combination of electron diffraction, synchrotron XRD and neutron powder diffraction.

Elsewhere in Sydney, researchers at the new Bragg Institute at ANSTO [5], in collaboration with Australian National University researchers, are studying a wide range of perovskite-based rare earth cobaltates. A phase boundary exists between compounds containing large and small rare earths. Powder neutron diffraction has been used in conjunction with other diffraction techniques to reveal cation and oxygen vacancy ordering within these materials. Others in the Bragg Institute are exploiting recent developments in powder diffraction techniques to solve and refine structures of natural and synthetic mineral specimens whose structures had previously been intractable. The Materials & Engineering Science unit at ANSTO [6] uses powder diffraction in research related to Synroc, a material for the long-term encapsulation and storage of radioactive waste. Powder diffraction is used to monitor materials preparation and to study rutile and perovskite variants.

At the University of Newcastle, north of Sydney [7], crystallographic and diffraction techniques have been applied to a variety of Materials Science problems. Perhaps the most spectacular is the study of combustion synthesis reactions using very fast in-situ neutron powder diffraction. Studies of the structure and phase transitions of giant piezoelectric effect material as both a function of temperature and of applied electric field have also yielded insights into the large piezoelectric response.

In Canberra, researchers at the Australian Defence Forces Academy [8], investigate the crystal and magnetic structures of rare earth intermetallic compounds as well as iron oxides and ferrites. The crystal structures of some 70 compounds in a new family of quaternary rare earth intermetallics – R3Co29M4B10 (M=Si, Ge, Al) – have also been determined along with the magnetic structures of some compounds in this series. The crystal and magnetic structures of strontium ferrites have been delineated as has the behaviour of zinc ferrites with particle sizes in the range ~ 8-50 nm.

In the West Australian Capital, Perth, powder diffractionists at Curtin University apply diffraction techniques in materials science, chemical and geological research, often related to primary resources [9]. Examples include the study of ceramic materials, particularly alumina and zirconia based ceramics for wear and corrosion resistant applications in engineering and cement processing, and the development of alumina matrix ceramics from bauxites to which additives from mineral sands are included. Other active areas are inorganic polymers (geopolymers), nanochemistry, crystallisation and biomineralisation.

At the South Australian Museum in Adelaide [10], researchers use powder X-ray and neutron diffraction for quantitative phase analysis in kinetic studies on the transformation of metal sulfides. The work aims to follow the course of reactions that occur in the formation and alteration of base metal deposits. Extensive use is made of PXRD in the identification and characterization of new mineral species.

Finally, in the AD Wadsley Minerals Laboratory [11] at CSIRO in Melbourne, researchers use in situ XRD studies to follow mineralogical changes during mineral processing. The research includes the study of the mechanism and kinetics of formation of the iron ore sinter phase, the pressure acid leaching of nickel laterite ores, and the mechanism and kinetics of Portland cement clinker hydration. The expertise developed in these in situ studies is being used to develop instrumentation for on-line PXRD measurement of mineralogy in industrial processes. This group has been active in the IUCr Commission on Powder Diffraction and coordinated the CPD Round Robin on quantitative phase analysis.

In New Zealand, powder diffraction is used principally within the universities and Crown Research Institutes. Of the Crown Research Institutes, Industrial Research Limited [12] has major research efforts in ceramic high-temperature superconductors, non-oxide ceramics (sialons and carbide cermets), and mesoporous materials. Landcare Research and Institute of Geological and Nuclear Sciences (GNS) Limited [13] have a shared interest in soil science, clay and rock mineralogy. Recent powder diffraction research at GNS has focused on geothermal studies, oil exploration, and massive sulphide deposits from undersea hydrothermal vents – the famous “black smokers”. At Victoria University of Wellington [14] nano- and micro- particles in glass ceramics for applications in radiation imaging are studied.

The future for powder diffraction in the region looks extremely bright, with two diffractometers under construction at OPAL and a high resolution instrument to be installed at the Australian Synchrotron.

References

[1] University of Sydney, New South Wales, Brendan Kennedy (b.kennedy@chem.usyd.edu.au)
[2] University of Sydney, New South Wales, Cameron Keppert (c.kepert@chem.usyd.edu.au)
[3] University of Sydney, New South Wales, Chris Ling, (c.ling@chem.usyd.edu.au)
[4] University of Sydney, New South Wales, Siggi Schmidt (s.schmid@chem.usyd.edu.au)
[5] Bragg Institute, ANSTO New South Wales, Mike James (mja@ansto.gov.auor kiw@ansto.gov.au)
[6] Materials Division, ANSTO New South Wales, Chris Howard, (cjh@ansto.gov.au)
[7] University of Newcastle, New South Wales, Erich Kisi (erich.kisi@newcastle.edu.au)
[8] University of New South Wales, Australian Defence Force Academy, ACT Stewart Campbell (stewart@phadfa.ph.adfa.edu.au)
[9] Curtin University of Technology, Western Australia Arie Van Riessen (a.vanriessen@curtin.edu.au) or (B.O’Connor@curtin.edu.au)
[10] South Australian Museum, South Australia, Allan Pring, (pring.allan@saugov.sa.gov.au)
[11] CSIRO Minerals, Victoria, Ian Madsen (ian.madsen@csiro.au) or Ian Grey (ian.grey@csiro.au)
[12] Industrial Research Limited, Wellington, New Zealand (martin.ryan@irl.cri.nz)
[13] Institute of Geological and Nuclear Sciences Limited (GNS Science), New Zealand. Raymond Soong (r.soong@gns.cri.nz)
[14] Victoria University of Wellington, New Zealand. Andrew Edgar (andy.edgar@vuw.ac.nz)

Interfacial structure by X-ray & neutron reflectivity

There is widespread interest in measuring the structure of surfactants, polymers, proteins, electrochemically produced species and chemical reactions at the air-water, oil-water and solid-liquid interfaces using the reflection of X-rays and neutrons. The only X-ray reflectometer in the region for the air-water interface was completed in 1996 at the Research School of Chemistry, ANU [1, 2] and made available to the community.

Research at the University of Canberra [2] has included the development of methods for electrochemical and grazing incidence studies on surfactant interfaces and semiconductors as well as considerations of the use of reflectivity for the determination of the real part of the anomalous dispersion correction f ', and the problems with this as a technique. Together with the Surface Chemistry Group at the University of Queensland [3] a focussing monochromator and image plate camera was developed and research performed on time resolved studies of film growth.

The Surface Chemistry Group [3] also uses neutron reflectivity measurements at ISIS in the UK. The films of interest are either on an air-water interface or on an air-solid interface. Recent work has shed light on the mechanism of action of a lung surfactant protein crucial for the breathing process in humans and animals. At ANU [1], time dependent studies of the growth of inorganic films (using surfactant templates at the air water interface) have shown the nanometre by nanometre build up and composition of the interfacial layers. The structure development has been followed from a simple surfactant surface excess through to a highly crystalline mesoporous film
thousands of layers thick. A key initial insight was obtained using constrained refinement fitting to X-ray and neutron reflectometry data collected on self-assembled mesoporous silicate films growing at the air-liquid interface.

New facilities for reflectometry research include the construction of a world class time of flight reflectometer for the neutron beam guide hall of the OPAL reactor.

[1] Australian National University (jww@rsc.anu.edu.au)
[2] University of Canberra (Dudley.Creagh@canberra.edu.au)
[3] University of Queensland (gentle@chemistry.uq.edu.au)

Diffuse scattering

[Diffuse scattering] Diffuse scattering in Wüstite, Fe1-xO, viewed down [001], recorded at the Advanced Photon Source at Argonne, USA. Wüstites are of considerable importance as they are thought to be a major constituent of the Earth’s lower mantle. The diffuse scattering is due to the formation of a complex distribution of defect clusters which contain both Fe2+ vacancies and Fe3+ interstitial ions.
Diffuse scattering research is represented through the work of researchers at the Australian National University in Canberra. One group [1] combines diffuse X-ray scattering methods with computer simulation to deduce the arrangement of atoms and molecules in disordered crystals. Diffuse scattering gives information on how neighbouring atoms or molecules interact with each other and the techniques have been applied by this group to disordered molecular crystals, guest/host systems such as urea inclusion compounds, non-stoichiometric inorganic materials and minerals, flexible framework structures such as silica polymorphs and their analogues, zeolitic materials, ferroelectric materials, alloys, and quasicrystal phases.

Another group at ANU [2] aims to understand and exploit the factors that determine structure and function in the crystalline solid state. Here, the interest is in the balance between local crystal chemistry, strain and order in a wide range of compositionally and/or displacively flexible crystalline solids. On the theoretical side, group theory, lattice dynamical calculations and bond valence sum analysis are the principal techniques. Crystalline systems investigated include non-stoichiometric solid solutions, displacively flexible zeotypic framework structures, ferroic phases, solid electrolytes, dielectric materials and incommensurately modulated structures. There is also a strong interest in determining the shapes of observed diffuse distributions in reciprocal space and then relating this back to multi-body correlations in real space. Systems to which this approach has been applied include the study of oxygen/fluorine ordering in metal oxyfluoride systems and various zeotypic microporous molecular sieve materials.

References

[1] Australian National University, Richard Welberry (welberry@rsc.anu.edu.au)
[2] Australian National University, Ray Withers (withers@rsc.anu.edu.au)

Crystallographic software and data definition

Australian scientists are active in the development of crystallographic software and processes for the definition, validation and publication of crystallographic data. Software packages currently available includes:

CRYSTAL_EXPLORER to display Hirshfeld surfaces and related graphics for molecular crystals [1] (to be distributed on www.theochem.uwa.edu.au/crystal_explorer);
DIFFUSE for calculating X-ray diffuse scattering from model disordered crystals [2];
DISCUS for defect structure simulation [3]; and
XTAL a general structure analysis package distributed as GNU software by Source Forge (xtal.crystal.uwa.edu.au) [4].

There is also close involvement in the definition and validation of electronic crystallographic data. In 1987, the Australian delegation to the General Assembly at the Perth IUCr Congress proposed that an approach should be developed for the electronic publication and archiving of structural data. This led to the development of the crystallographic information file (CIF) now in wide use for data exchange. Perhaps more importantly, the CIF approach focused the crystallographic community on the need for precise identification and definition of the myriad of data items used in the discipline. The subsequent adoption by the IUCr of a series of data dictionaries means now that CIF data may be automatically and comprehensively validated and checked when submitted electronically to journals and databases. This approach was initially introduced for manuscripts and data submitted to Acta Crystallographica C while Syd Hall (University of Western Australia) was Editor. Its success subsequently led to the creation of Acta E, a fully electronic journal, and more recently its macromolecular equivalent Acta F (Mitchell Guss, University of Sydney, joint Editor). The pivotal role now played by ontologies in data exchange has resulted in the compilation of International Tables Volume G entitled: Definition and exchange of crystallographic data (Syd Hall, joint Editor). Currently a new data definition language (StarDDL) is being prototyped at the University of Western Australia [5] in collaboration with researchers at Rutgers University in the USA.

References

[1] University of Western Australia, Mark Spackman (mas@cyllene.uwa.edu.au) and Dylan Jayatilaka dylan@theochem.uwa.edu.au
[2] Australian National University, Richard Welberry (welberry@rsc.anu.edu.au)
[3] Currently Los Alamos National Laboratories, Thomas Proffen (tproffen@lanl.gov)
[4] University of Western Australia, developed by many researchers, coordinated by Syd Hall (syd@crystal.uwa.edu.au)
[5] University of Western Australia, Syd Hall and Nick Spadaccini (nick@csse.uwa.edu.au)

Crystallographic organizations

Crystallographers in Australia and New Zealand are represented by three separate but equally important organisations. The first two are the New Zealand and Australian National Committees for Crystallography. In New Zealand, the membership represents all the centers where crystallography is practised. In Australia, the committee is formed by the Australian Academy of Science which is the adhering body to the various International Unions and hence the International Union for Crystallography (IUCr). For example, it is the National Committee that nominates the Australian delegates to the General Assembly of the IUCr. In New Zealand, the affiliation to IUCr is through the Royal Society of New Zealand.

The third organization is The Society for Crystallographers in Australia and New Zealand (SCANZ), which has membership open to any scientist or student with an interest in crystallography. Originally the Society of Crystallographers in Australia, there has been regular participation over many years by New Zealand crystallographers and this led in 1999 to the formal incorporation of New Zealand in the society, which thus became SCANZ. The Society organises scientific meetings, awards student travel scholarships and nominates the Australian representatives on the council of the Asian Crystallographic Association (AsCA), one of the three regional associates of the IUCr. SCANZ is run by a council which is elected by the membership. Meetings of SCANZ are held regularly (about every 18 months) but with uneven frequency so as not to clash with IUCr congresses or major meetings of AsCA. The last meeting was held in Marysville, Victoria in March 2005 and the next SCANZ meeting will be held in 2007, hosted by Sydney, New South Wales.

Following the successful IUCr Congress and General Assembly held in Perth, Western Australia in 1987, residual funds from the meeting were invested for the purpose of supporting the travel of young crystallographers from Australia and New Zealand to meetings of SCANZ, AsCA and the IUCr. In addition, “1987 Fellowships” are awarded to leading crystallographers to present their work at a SCANZ meeting. The Scholarships and Fellowship have been named for Ted Maslen, who played a leading role in the establishment of SCANZ and in the successful organization of the 1987 Congress. His untimely death at a relatively young age was a loss to crystallography everywhere, and it is fitting that he be remembered by the Scholarships and Fellowship that bear his name. 

Contributors (in alphabetical order)

Ted Baker, Peter Colman, Hans Freeman, Graeme Gainsford, Richard Garrett, Ian Gentle, Mitchell Guss, Syd Hall, Chris Howard, Geoffrey Jameson, Brendan Kennedy, Shane Kennedy, Peter Lay, Jennifer Martin, Jim Metson, Rick Millane, Michael Parker, Rob Robinson, Ward Robinson, Mark Spackman, Andrew Stevenson, Richard Welberry, Allan White, John White, Steve Wilkins