Next year we will have the International Year of Crystallography, however it is my opinion that this science is slowly dying mainly because it is perceived by other scientists just as a technique (X-ray diffraction or sometime X-ray crystallography) to provide molecular structures and only rarely as a real science, connected to many others (like chemistry, physics, mathematics, biology etc.) What do you think?
This question from Piero really hit a nerve with me, since I was recently invited, and have accepted, to try to assemble a “Themed Issue” in the general area of Crystallography for the Open Access Journal Chemistry Central, for which I am an Editorial Board Member. The idea is that I choose a particular Theme, write an introductory/ promotional Editorial Review, and invite colleagues to contribute papers which link to the theme.
I am sure most of you will mutter “oh no, not another one”, bearing in mind the current calls for contributions to a special issue of Acta B and the new IUCR OA Journal, starting in 2014, but I felt it might be useful to post a summary of my thoughts on how I plan to structure this Themed Issue, as a quick and relevant response to this prompt from Piero.
I have to admit that I have heard comments like those Piero quoted many times, usually made by colleagues competing for funding or promotion, but I had the feeling that moods were changing. There are now many researchers who would identify their area of expertise as Crystallography, who are really Applied Chemical or Physical Crystallographers, using the capabilities of the technique to chart new, exciting and relevant developments.
Looking back to the 60’s and early 70’s, and the start of my own independent career, it was clear that the young crystallographers of my generation, helped by some very skilled mentors and experts, were really involved in what became the Chemical Crystallography revolution. From that time, crystal structure analysis was able to feed back real information into active researches in synthetic organic, inorganic and organometallic chemistry programs, where the chemists were not always sure what they would get from a particular reaction, and where all kinds of new compounds were being discovered. Very often, the new compounds were targeted as results from X-ray studies had identified a new kind of structure. This, I think is the kind of work which became recognised as "Service Crystallography" and, of course it is still a valuable activity, much improved by the continuing development of new techniques and instrumentation. However, the same developments have prompted new kinds of study, still within the remit of Chemical Crystallography. Thus, in addition to the classic, and still important, collaboration between synthetic organic, bioorganic and inorganic chemistry and crystal structure analysis, we are now involved in molecular property/solid state property correlations, crystal structure design and engineering, and theoretical studies, where, from the start, data and knowledge from X-ray structural studies marched side-by-side with the development and parameterisation of computational chemistry methods in molecular and solid state science. This combination is feeding back into crystal structure energy calculations, charge-density analysis, crystal structure prediction, and many aspects of material science and properties.
So, this belief has prompted me to focus the CC Themed Issue on the successfully continuing area of “Chemical Crystallography”. I can envisage that this environment, and the thematic series of keynote papers may therefore include topics (notwithstanding the hype around some of them!!) such as:
o New compounds and new structures, including multi-component systems
o Structural systematics
o Crystal Engineering
o Intermolecular interactions, including aspects of hydrogen and hypervalent bonding
o Structure-property relationships
o Crystal structure descriptors and crystal structure data mining
o Crystal structure prediction and computational chemical crystallography
o Charge Density Studies
etc, etc - I am sure there are others, and I would be very glad to hear any further suggestions. At the same time, I would be pleased to have any feedback with offers of papers or suggestions for possible authors known to be preparing block-buster papers with new ideas or exceptional results, which would fit in with my theme. I will have a few waivers or reduced OA fee tickets, to help colleagues whose Institutions or research grants do not have OA funding. Let me know.
So, Piero, I hope this rambling contribution provides a bit of positivity, and helps to prompt some more positive comments and replies to your question. For sure, I know funding is tight everywhere, but it has been before, and has recovered, so I am much more positive than Julian about the possible turn around - I think it is already underway. But then I have always been a great optimist!
Regards and Best Wishes.
Mike Hursthouse
Southampton, 23/10/13.
"Mit Vorhersagen muss man vorsichtig sein, besonders wenn sie die Zukunft betreffen". These words (or at least very similar words) are from a well known scientist. It may look like that Crystallography is slowly dying by just extrapolating the experiences of the near past and present moment, but often things are more complex as to just predict them correctly by linear interpolation. So it may well be that this trend is turned around by unforeseen events in the future. Who knows?
This question from Piero really hit a nerve with me, since I was recently invited, and have accepted, to try to assemble a “Themed Issue” in the general area of Crystallography for the Open Access Journal Chemistry Central, for which I am an Editorial Board Member. The idea is that I choose a particular Theme, write an introductory/ promotional Editorial Review, and invite colleagues to contribute papers which link to the theme.
I am sure most of you will mutter “oh no, not another one”, bearing in mind the current calls for contributions to a special issue of Acta B and the new IUCR OA Journal, starting in 2014, but I felt it might be useful to post a summary of my thoughts on how I plan to structure this Themed Issue, as a quick and relevant response to this prompt from Piero.
I have to admit that I have heard comments like those Piero quoted many times, usually made by colleagues competing for funding or promotion, but I had the feeling that moods were changing. There are now many researchers who would identify their area of expertise as Crystallography, who are really Applied Chemical or Physical Crystallographers, using the capabilities of the technique to chart new, exciting and relevant developments.
Looking back to the 60’s and early 70’s, and the start of my own independent career, it was clear that the young crystallographers of my generation, helped by some very skilled mentors and experts, were really involved in what became the Chemical Crystallography revolution. From that time, crystal structure analysis was able to feed back real information into active researches in synthetic organic, inorganic and organometallic chemistry programs, where the chemists were not always sure what they would get from a particular reaction, and where all kinds of new compounds were being discovered. Very often, the new compounds were targeted as results from X-ray studies had identified a new kind of structure. This, I think is the kind of work which became recognised as "Service Crystallography" and, of course it is still a valuable activity, much improved by the continuing development of new techniques and instrumentation. However, the same developments have prompted new kinds of study, still within the remit of Chemical Crystallography. Thus, in addition to the classic, and still important, collaboration between synthetic organic, bioorganic and inorganic chemistry and crystal structure analysis, we are now involved in molecular property/solid state property correlations, crystal structure design and engineering, and theoretical studies, where, from the start, data and knowledge from X-ray structural studies marched side-by-side with the development and parameterisation of computational chemistry methods in molecular and solid state science. This combination is feeding back into crystal structure energy calculations, charge-density analysis, crystal structure prediction, and many aspects of material science and properties.
So, this belief has prompted me to focus the CC Themed Issue on the successfully continuing area of “Chemical Crystallography”. I can envisage that this environment, and the thematic series of keynote papers may therefore include topics (notwithstanding the hype around some of them!!) such as:
o New compounds and new structures, including multi-component systems
o Structural systematics
o Crystal Engineering
o Intermolecular interactions, including aspects of hydrogen and hypervalent bonding
o Structure-property relationships
o Crystal structure descriptors and crystal structure data mining
o Crystal structure prediction and computational chemical crystallography
o Charge Density Studies
etc, etc - I am sure there are others, and I would be very glad to hear any further suggestions. At the same time, I would be pleased to have any feedback with offers of papers or suggestions for possible authors known to be preparing block-buster papers with new ideas or exceptional results, which would fit in with my theme. I will have a few waivers or reduced OA fee tickets, to help colleagues whose Institutions or research grants do not have OA funding. Let me know.
So, Piero, I hope this rambling contribution provides a bit of positivity, and helps to prompt some more positive comments and replies to your question. For sure, I know funding is tight everywhere, but it has been before, and has recovered, so I am much more positive than Julian about the possible turn around - I think it is already underway. But then I have always been a great optimist!
Regards and Best Wishes.
Mike Hursthouse
Southampton, 23/10/13.
Dear Mike, dear all
reading your post, I have the impression you believe I am one of those "competitors" that like to put down crystallography. Instead, I am (proud to be) a crystallographer, and I have also to write a paper for a special issue to appear next year.
I am not so sure if I should be defined a pessimistic crystallographer, or likely a realistic one. Anyway, I summarize the main observations that lead me to pessimism:
- colleagues in chemistry and other natural science areas do not support much crystallography, in fact they have worked hard and eventually succeeded to cancel most of the chairs in crystallography. This was in part possible because crystallographers were not able to demonstrate how important could be the many topics that you mentioned above and the sole crystallographic service was understood as valuable (but also quite immediate nowadays).
- not only research funding is limited, but also technological investments are limited now, as demonstrated by the rather small price of diffractometers when compared to similar equipment relevant for other scientific fields. This means that progresses are expected to be smaller in the next future.
- Many of the topics you mentioned above have been highly simplified by crystallographers for inorganic / metal-organic or organic chemists, similarly to what happened to quantum chemistry in the '80s . Exactly as it happened to quantum chemists, they were not able to obtain sufficient return from this, impressive, work. As a results, serious quantum chemists publish their papers, at the best, in J. Chem Phys, whereas almost uneducated Gaussian users can publish in JACS, esteemed crystallographers publish fundamental science in Acta Cryst, and some unexperienced ones publish bad and trivial structures in Nature.
Will things change? Maybe, but how?
best
Piero
This does not belong to Pieros question but to Michaels answer: I suggest to include the topic "Data- and fitquality indicators" or "Systematic Errors". My feeling is that it is time to focus more attention into this direction and this can be done by giving it more space.
Dear Piero,
Sorry, I did not imply in any way that you were one of those "competitors" trying to put crystallography down. I was agreeing with you that there always have been, and still are, many people like that, and I have battled with them for most of my career. Fortunately, I have been lucky to have a few really good senior colleagues who supported me. We do not have many Professors of Crystallography either - "Structural Chemistry" is about as close one can get! I also agree that there are many quantum chemistry package users - just like the many crystallography package users, who can get the answer they want by just pressing a few buttons, learn a few basics - and publish many papers. The point I was trying to make is that, in spite of all this, our subject has still attracted a number of very capable scientists who are knowledgeable and skilled enough to develop innovative procedures for tackling serious and fundamental problems, and this is why I believe chemical crystallography is now a much more serious subject. However, the problem you highlight about publishing is not about the quality and importance of the work, but the citation driven masses, and some authors and Journals manipulate this for impact factor reasons. Now that is something I really would like to tackle, but the community is very unbalanced. Most of my citations come from papers created by Service Crystallography, which has always provided my instrumentation and funding. Papers relating to my own work on Structural Systematics routes to learning more about crystal structures, take long to gather data and to prepare, but get few citations, partly because few people are working in the area and those to whom the results may be of interest do not cite - the classic "not invented here" syndrome!! I would like to think that things will improve, but I am resigned to the fact that, from my "retirement home", I am not going to make much more impact. But I will try, as long as I can!
Best wishes
Mike
Good question! I'll read your comments and then join you intelligently.
http://www.flickr.com/photos/85210325@N04/10221987094/
Here are some observations and thoughts edited by P.P. Ewald on a similar topic 50 years ago:
http://www.iucr.org/__data/assets/pdf_file/0016/718/START.pdf
This section is a classic by W.L. Bragg himself. Very interesting history and depth of perception: http://www.iucr.org/_data/assets/pdf_file/0014/725/chap8.pdf
"I end this lecture with a graph, in which the years are plotted horizontally, and the number of parameters in typical structure determinations are plotted vertically on a logarithmic scale. The curve starts with one parameter in 1913. It shows a sharp break at the exciting present time, and in tracing its course I have ventured with some confidence to assume that the haemoglobin structure will be completed next year. If we prolong the graph we conclude that we shall reach the million mark in 1965. This is not so improbable as might seem; is there not hope that by that time we shall know the atomic architecture of a simple virus? How the million parameters will be listed in Acta is a problem I leave to the editors at the time. I have high hopes that I shall see the great day." W.L. Bragg
Hundred years since the Braggs got the Nobel Prize in 1913!
http://www.theguardian.com/science/video/2013/oct/09/100-years-x-ray-crystallography-video-animation?goback=%2Egde_3614857_member_5796412999388381186#%21
Google Doodle: How Rosalind Franklin photographed DNA csmonitor.com
Thursday's Google Doodle celebrates the birthday of Rosalind Franklin, the first photographer of DNA.
http://www.csmonitor.com/Innovation/Tech-Culture/2013/0725/Google-Doodle-How-Rosalind-Franklin-photographed-DNA-video?goback=%2Egde_2683600_member_231584534%2Egmr_2683600%2Egde_2683600_member_260830290
http://www.flickr.com/photos/85210325@N04/10221065324/
Crystallography is the science of the crystals, that is, crystalline solid materials (minerals and chemical materials). Currently is an elective course in some universities in the degrees of experimental sciences. Unfortunately some commercial houses sell some useful crystallograhic instruments and software in the field of crystallography considering that results may be obtained without having a basic crystallographic previous knowledge. This is a problem that is indirectly affecting many young performed investigations without having any idea of some basic crystallographic concepts (Miller indices point symmetry groups, space groups, Bravais lattices, diffraction by crystals, .... ). Despite this comment for me the crystallography still has a good future in the field of experimental and related sciences.
José ! "idea of some basic crystallographic concepts (Miller indices point symmetry groups, space groups, Bravais lattices, diffraction by crystals, .... )."
I suffered from the same ailment. Must have been "day dreaming" in class when this stuff was taught to me more than 3 decades ago. However, it was only when I started observing XRD images in 2D and real time (1984-1988) did I really understand these concepts thoroughly. I diversified in the late 1980's in to Real Estate. When I jumped back in around 2004, I was flabbergasted by the lack of 2D real time imaging tools in present day XRD investigations. Folks are still inextricably wedded to the ubiquitous 0D Point/Scintillation type detectors. This was aided a bit by a little "brain wash" from the XRD equipment manufacturers. These type of detectors have been in use since the Braggs. So, the idea that Crystallography is at a "dead end" is premature without the full implementation of the 2D detectors in XRD analyses.
Here is a classic book and some relevant excerpts:
X-ray Diffraction In Crystals, Imperfect Crystals and Amorphous Bodies by Andre Guinier. 1962 - Great book! Worth acquiring for your XRD collection.
(pp. 162-163) 6.3.5. "Comparison between the Photographic and Counter Methods
It is obvious that the Geiger Counter and the ionization chamber have the advantage of precision and sensitivity. They alone permit a quantitative study of scattering. However, point by point measurements in reciprocal space are lengthy, while the photographic method gives directly a picture of the scattering in a single experiment over a large surface of reciprocal space. The resolving power of the film is excellent. Thus, sharply defined scattering regions, for example on rows or on planes of reciprocal lattice, show up very clearly on photographic film but are difficult to detect with a counter.
Let us note also that the counter is "blind". In many cases inaccuracies in the setup produce stray scattering which is easy to detect on the photographic film but which can spoil a series of experiments made with a counter.
The two methods are therefore complimentary and it would not be advisable to neglect one in favor of the other. The photographic method is admirably suited to the qualitative exploration of an unknown pattern, since one can then find totally unexpected phenomena. The counter is necessary for quantitative measurements on a pattern which is already known qualitatively."
This was printed in 1962. This has to be considered in light of the present day 2D detectors that combine the benefits of the counter & the film in one. These writings indicate some causes for the present day inertia of moving from the 0D to the modern 2D detectors. The spatial "blindness" of the 0D scintillation counter/detector is the principal reason even experienced experts using XRD are ambivalent about the 0D XRD data/results.
"The intellect has little to do on the road to discovery. There comes a leap in consciousness, call it Intuition or what you will, the solution comes to you and you don't know how or why." Albert Einstein
http://www.flickr.com/photos/85210325@N04/10242907544/
One perfect example of the archaic state-of-the-art in XRD is the continued use of conventional 0D point counters for the XRD Rocking Curve measurements. These measurements usually take 10 min to an hour depending on the resolution desired and SNR available. The data obtained is an average parameter over a large sampling area. The Nano structural resolution possible with the X-ray rocking curve technique is in the FEMTOMETERS. However, this resolution is meaningless if one averages such measurements over large (typically 1mm X 2 to 10mm) sampling areas.
The paradigm changes remarkably if one uses a real time 2D X-ray detector for such measurements. I'm highly bullish about Bragg XRD Microscopy. This method uses the deviation from IDEAL BRAGG CONDITION as a quantitative measure of the crystalline Nano structure. The potential is phenomenal! The spatial resolution currently possible is in the 1-5um range. Using clever optics (e.g., ACT - Asymmetric Crystal Topography) it is feasible to get down to sub-micron spatial resolution. The ultimate spatial resolution possible would be in the range of the wavelength of the incident X-ray beam. Compared to conventional XRD rocking curve measurements the time and data advantage of the real time 2D method is in excess of 6-9 orders of magnitude.
We have developed Bragg XRD Microscopy with out any external financial support in the recent past. However, back in the 1980's the work was amply funded by organizations such as DARPA, ONR, NASA, US Army Night Vision Lab. My mentors for this work were Dr. Sigmund Weissmann of Rutgers Univ. (NJ) and Dr. Robert E Green Jr. of Johns Hopkins Univ. (Baltimore, MD).
Bragg XRD Microscopy may be utilized both in reflection and transmission modes. In contrast with SEM/TEM, this method is NDE, in situ and requires no vacuum.
The YouTube video "Play List" below contains all the raw Bragg XRD Microscopy data for a variety of materials systems. You may download and analyze for yourself if and when you have the capability. Please turn off Google Ads and the Music (listen to this instead if you like: http://www.shoutcast.com/shoutcast_popup_player?station_id=98721&play_status=1&stn=WJOE - Grateful Dead Radio - All Day, Al...) to minimize distractions.
Suggestions for improving are always welcome!
https://www.youtube.com/watch?v=dFCQS8oUyT0&list=PL7032E2DAF1F3941F
BTW I'm one of the few on both RG & LinkedIn that proudly wears the "Crystallographer and Materials Scientist" label although it is only an avocation to me presently. I do XRD for personal pleasure now. Not looking for any recognition or funding. I'm oblivious to all the "rat race" parameters such as RG score, publications, ratings etc. I'm so convinced in my own thoughts over the past 3 decades that nothing shall deter me from my quest. I expect to receive the latest model Bragg XRD Microscope within the next 10 days. We're excited about testing it both at Brookhaven National Lab and US Air Force Research Lab (Dayton) soon. Incidentally, I've used the device successfully even on the old "Dinosaur" diffractometer built (even before I was born, older than dirt!) by GE (Diano), besides the modern Panalytical X'Pert or MRD type equipment. Let's get back to the future!
I'm highly impressed with the RG scores that Piero, Michael, Kenneth and José have accumulated. I know that was not a trivial task. Your accomplishments are impressive indeed. Congratulations!
Please review my LinkedIn profile below for a lot more information:
http://www.linkedin.com/profile/view?id=63121884&trk=nav_responsive_tab_profile
We could certainly use your help and expertise to get better. Please join this LinkedIn group "X-ray Diffraction Imaging for Materials Microstructural QC" and share your knowledge and wisdom with us:
http://www.linkedin.com/groupItem?view=&gid=2683600&type=member&item=238135655&qid=d56b49fd-cc5a-48cb-9f5a-a492d9496ace&goback=%2Egmr_2683600
Group Statistics:
http://www.linkedin.com/groups?groupDashboard=&gid=2683600&goback=%2Egmr_2683600%2Egde_2683600_member_238135655&trk=groups_include_group_profile_snippet-tpnv-grp-sts&goback=%2Egmr_2683600%2Egde_2683600_member_238135655
http://www.flickr.com/photos/85210325@N04/8029307446/in/set-72157632724026971
Being an enzymologist myself, I think of X-ray crystallography mainly for protein structure determination. The submission rate at PDB is still exponentially growing, even for the non-redundant data set. And drug development is seriously hampered by the lack of crystal structures of membrane proteins, which make about 70% of known drug targets. The recent use of X-ray lasers (DOI: 10.1126/science.1233209) will certainly revolutionize this field.
Thus, at least as part of collaborative research projects in drug development or enzymology (amongst other fields) enzymology is still very much alive!
Ken! "Personally, I don't know where "Crystallography" was ever anything other than a university "elective", if even that." - I tend to agree. But, I intend to change that as it changed for me once I was able to see real time XRD data. I will make a difference. The Bragg XRD Microscope will change the paradigm. It would be the best tool for any teaching institution for XRD. I intend to be the Protagonist-in-Chief!
http://www.flickr.com/photos/85210325@N04/8447574087/
Ken! "how out-of-touch I have become in my retirement"
Not sure when you retired but you cannot retire your brain from thinking. Best thing you'd ever do for that 3 lb muscle. Don't let it atrophy! Keep on keeping on Ken!
Don't bottle them ideas! Spit 'em out! Never get too serious!
http://www.flickr.com/photos/85210325@N04/10221987094/
Hello Piero, because I know you as a crystallographer I can said that I understand your points well.
I know from my personal experience about calling crystallographers "parasites on the results of people REALLY WORKING on syntheses" due to their co-authorship of nearly all articles from the department. I know about "trained monkeys" (slowly becoming crystallographers) which obtained "an offer one can't deny" that they will be co-authors only at every third article consisting of the structures solved by them - one of them then leaved the faculty, second one resigned to do anything with crystallography. After this issue, certain coryphaei continued claiming that they in fact don't need the crystallography, but at the same time they exploited fellow-feeling of their colleaugues abroad (interestingly they hadn't any problem with their co-authorship here :D) which had enough funding to do this favor for them. It was pretty crazy - they travelled 100-500 km with the crystals having problem to survive transport between labs inside the building :D
Now, with high-throughput diffractometers, hundreds articles of the crystallographer are "the issue" for synthetic chemists with only tenths of them. It seems like they "aren't doing anything". What is worse, we crystallographers are in fact doing harm to us when we are disseminating informations about the routine structure (i.e. 80-95 % of measured ones) is at most 20 minutes of solution/refinement (but at least whole day to analyse and polishing the CIF, not talking about energy/consumables costs which at this time nobody wants to pay!), that even (at least non-merohedral) twins are almost routine, etc. They don't know what it means "routine" and what is the background of this "routine", possibly they realized that it is like mixing up the content of two beakers, they simply realized that all what is called "routine" must be put down - "It is for sure not any big science when you obtained the results in such short time!" (a great irony if it is said by somebody not capable to learn even "trained monkey" level). It is the same like 15 years before, but 15 cycles of the least squares was 20 minutes not 10 seconds like today. It seems like we become a kind of dumbasses thanks to advancements in computing speed and automation (which were done by us to help us with routine structures to obtain more time for the challenging ones), like if the time of waiting for calculation finishing was making us the scientists. And when I face real crystallographic problem I never seen before (so I need some time for it - between their "routine" structures) they are suspisious about my laziness or a kind of sabotage. Crazy when it is said by quantum chemist without any crystallographic background which looking at CrysAlis screen with just acquired image said "oh yes I can see some atoms here already!" (and then talking everywhere about "he is doing nothing, the machine alone do it for him!"). And such people are judging us according to similarly absurd statements.
At the end we have the situation when are very real presses to put the teaching of the crystallography to the minimum. Now I am having some indices that I have put down most of it - when we finally obtained the machine and I am in severe need of co-worker! and possibly I will be happy when the final loses will be one half of the hours. And it is not only about structural crystallography classes, "crystallography" for our bosses is also crystallochemistry (approx. according to Ulrich Mueller's Structural Inorganic Chemsitry + basics of the supramolecular chemistry (selected chapters from Jon Steed's famous book), crystal engineering and charge density studies). All the presses are towards "purely practical" approach to produce "trained monkeys" without any complex background (but we are talking about graduate courses!). It is extremely unlikely when the professor warranting our specialisation is telling something that inorganic chemist don't need so much crystallography, especially single crystal methods (he is in fact material scientist and powder methods are almost all what HE need).
I am sick of it. I know so well what are you talking about, the details are possibly locally different, but finally it is about the same.
Have you anybody read Kurt Vonnegut's Timequake?
When selling Smart X2S or XtaLab mini to the synthetic chemists without any deeper knowledge, companies are in fact "giving them our heads by tweezers" (I read it in Czech so I don't know what was original English phrase).
I am curious what such "accelerated crystallographer" will do/tell when he approach something like modulated structure, quasi-crystal or "only" a kind of merohedral twinning...
Dear Piero,
This is as silly as it is intended to be a provocative question. Every human activity can be mundane or full of excitement and novelty. Many people watch TV every day but very few make new TV sets or new transmission methods discoveries. These happened after almost 60 years and now we have flat TVs in HD.
Crystallography as a fully mature science. It can be used in a utilitarian incarnation by technology people or by other scientists as a support science. In a similar manner to how everybody uses computers these days, but this does not impede computer scientists to be innovators. Besides, excellent points raised by Michael, Eric and Kenneth, I would only cite the list of my unorthodox recommendation for the most narrow field as it is protein refinement that I shared in some other discussions on RG. I do not even mention real science problems like general solution to the phase problem or how to deal with real time crystals constructed from let's say five unit cells. In the future we will have many more exciting problems associated with free electron lasers and holography, dynamical retuning of wavelengths and real time changes in structures. Structures gave us so much insight into what is life (how proteins are ordered and disordered at the same time) that I do not really worry about running out of research issues in a near or even remote future.
There still would be one button crystallography installations producing structures in the chemistry or geology labs producing standard structures. But they would not be if not for innovative peoples like Karle or Sheldrick. People pushing the buttons do not need to understand the history or even the theory behind it, but the same applies to TV viewers.
Now it comes my list of recommendations for the protein refinement, and every single point can be made into a serious science project. If do not care about it just disregard it.
1) For instance, we should refine the structures on the entire diffraction pattern not only the pseudo-Bragg peaks that we arbitrarily selected by our indexing and integration procedures that "create" the data versus "recording" them. The amount of info in the inter-Bragg spaces is just staggering.
2) We should collect all the data in P1 and determine the "real" symmetry after we refine all the copies of the molecules, even though we solved and initially refined the structure in the particular space group.
3) We should always refine hydrogens (including on water molecules).
4) We should refine the solvent as it has the structure many angstroms away from the protein surface.
5) We should never use dummy atoms (particularly with occupancies 0) or truncate the residues.
6) We should refine ensembles (for instance invisible loops should have the "NMR-like" multiple representations with correct stereo-chemistry.
Before discussing whether or not crystallography is going to die one has to define what you mean by "crystallography". Have a look in the special issue on "What is Crystallography?" of Zeitschrift für Kristallographie Vol. 217,Issue 7-8, 2002
Dear Dr. Piero,
I don't think that the the field of crystallography is dyeing when the other scientists from other areas also involving and participating in this field. As they started working on this area it indicates that this is the time for us to take the crystallography to the next level of understanding and application to other fields. They are actually decreasing our work of structure determination and saving our time to analyse the structure in more scientific way to address the property issues. So the crystallography will never die and it is taking another route to grow fast. We can expect the better growth and stability of crystallography field when it become a common area to all of us.
Dear Walter
I agree that a definition is always necessary, in science, before starting any analysis. I am of course aware of that paper, as well as of those discussing what is a crystal.
The problem, however, is not what we crystallographers, or better "self-styled" crystallographers, define as crystallography. The problem is what the rest of the scientific community defines as crystallography. It is clear that we do not want this discipline to die and we are very careful to even minor changes of the field directions.
I do not think crystallographers will suicide, however I think that mistakes made during the "oldie goldies" may severely affect the external perception of crystallography.
Apart for the inhabitants of Masada in 73 a.d., I am not aware of any population who deliberately destroyed themselves, though many empires dissolved, mainly due to internal errors (the Roman empire, to mention one).
My question could be rephrased as: is there a future for what we think it is crystallography? (which does not mean: is there a future for those who are called crystallographers?)
A small remark concerning Dieter Schwarzenbach. At the joint meeting of the Swiss Physical Society and Swiss crystallographic society he gave a talk on the major achievements of crystallography and he addressed the main expectations for the future, among which he mentioned the single molecule structure (maybe possible in the future with the FEL). I asked him if this was still "crystallography" and he admitted that a revision of the definition would be necessary. Indeed!
I feel Liliputian among this erudite company. There is the opportunity for me! Lots of room to grow & learn! No impending demise of crystallography for me! Being a Metallurgist, I've barely scratched the surface when it comes to bio-crystals and other materials with Semi and Para crystalline states.
There are many interesting sub-topics evolving out of this diverse group of "Crystallographers" already that needs individual attention. Never-the-less, the advent of technology and cost effective miniaturized imaging tools have essentially change the paradigm now for crystallography, in my humble opinion.
The discussion of "what is crystalline?" is in itself fascinating to me. Here is an example of GaAs Mono-crystal imaged using the Bragg XRD Microscope. The experimental XRD Rocking Curve Profile is near-identical with the theoretical profile:
http://www.flickr.com/photos/85210325@N04/10502393183/
The fit is uncanny! The deviation from IDEAL BRAGG PROFILE is mostly on the lower Omega side below the FWHM. This indicative of "excess defects" due to missing Ga (lower atomic radius) layers in stacking faults. This data has FEMTOMETERS resolution through reciprocal space for individual examined VOXELS on the sample. The spatial resolution limit presently is in the 1-5 Microns with sub-micron capability and better. In this example, for instance, the Omega angular resolution was
Hi,
What is the future of Crystallography? Crystallography will succumb to automation. The Crystallographer as profession will disappear as the only thing left to do is make crystal, which other people are more qualified can to do better. In addition the type of X-ray used will only be available in large centers.
HI Terence. Anyway someone will have to program those robots, do not you think so?
I aim to disprove Terence's archaic hypothesis "Crystallographer as profession will disappear"! I've been hearing this cliché since I left the field in the 1980's. Kind of like the Armageddon theory. Get an imagination folks! Wise words from many of the founding fathers of XRD and their hopes and aspirations for the future of crystallography were quite bullish. As we probe further and deeper into the reciprocal space the Crystallographer (analyses) becomes quintessential. Automation has so much to learn from the 3 lb. miracle, The Human Brain!
Thales has been involved with 2D X-ray Imaging for more than 3 decades but have no clue about its full application potential in crystallography and materials characterization yet. The equipment is superb but not many crystallographers have worked that "App" to the fullest potential yet mainly because of the exorbitant cost. Those days of selling Million Dollar X-ray Imaging system are gone. We now have the super compact and super fast available at a reasonable price. Kind of like the Lamborghini versus Honda! No more esoteric science only, syndrome.
There is so much to explore! Someone mentioned the relevance of the diffused scattering data. That is only one aspect! There are so many wonderful possibilities. Here is an example of the Nano structural details one could delve into with a typical MBE grown Super Lattice Epitaxial film and the substrate below non-destructively:
http://www.flickr.com/photos/85210325@N04/10502186495/
GaSb Substrate below Epi:
http://www.flickr.com/photos/85210325@N04/10502940644/
InAs/InAsSb MBE Epi 25nm period 10 periods:
http://www.flickr.com/photos/85210325@N04/10502189096/in/photostream/lightbox/
Data, samples and XRD equipment was provided by the good folks at the US Air Force Research Lab @ the Wright Paterson Air Force Base. The GaAs theoretical Bragg Profile was provided by the good folks at Bruker (Wayne Lin). The 2D Real Time Bragg XRD Microscope was provided by Onsight Technology USA. The research was funded entirely by Onsight Technology USA. Thanks to all participants!
http://www.flickr.com/photos/85210325@N04/10502186795/
Piero,
I’m not of this profession just experiencing people saying for years we can’t get crystals. If you look at the analysis methods the software is standard and the producers of the structure move on to the next never becoming experts in what they have produced. Things like the ribosome and mitochondria seem to be too difficult. In addition the 3-d structure as determined has little reflection of it true biological function as in the cell where things happen.
X-ray Diffraction In Crystals, Imperfect Crystals and Amorphous Bodies by Andre Guinier. 1962 - Great book! Worth acquiring for your XRD collection.
(pp. 162-163) 6.3.5. Comparison between the Photographic and Counter Methods
"It is obvious that the Geiger Counter and the ionization chamber have the advantage of precision and sensitivity. They alone permit a quantitative study of scattering. However, point by point measurements in reciprocal space are lengthy, while the photographic method gives directly a picture of the scattering in a single experiment over a large surface of reciprocal space. The resolving power of the film is excellent. Thus, sharply defined scattering regions, for example on rows or on planes of reciprocal lattice, show up very clearly on photographic film but are difficult to detect with a counter.
Let us note also that the counter is "blind". In many cases inaccuracies in the setup produce stray scattering which is easy to detect on the photographic film but which can spoil a series of experiments made with a counter.
The two methods are therefore complimentary and it would not be advisable to neglect one in favor of the other. The photographic method is admirably suited to the qualitative exploration of an unknown pattern, since one can then find totally unexpected phenomena. The counter is necessary for quantitative measurements on a pattern which is already known qualitatively."
This was printed in 1962. This has to be considered in light of the present day 2D detectors that combine the benefits of the counter & the film in one. These writings indicate the present day inertia of moving from the 0D to the modern 2D detectors. The spatial "blindness" of the 0D scintillation counter/detector is the principal reason even experienced experts using XRD are ambivalent about the 0D XRD data/results.
http://www.flickr.com/photos/85210325@N04/10515372183/
Just to mention that Crystallography is very wide and critical field, and does not only concern conventional XRD in the lab as some people (particularly in life sciences...) think... Scientists who are involved in high-resolution microscopy and related techniques, such as HAADF-STEM, or even people involved in -other than XRD- X-ray spectroscopies (e.g. EXAFS), have been also doing, in fact, Crystallography. Important Nobel Prizes in Chemistry, including those of Prof. Yonath and Prof. Shechtman, are also Crystallography. Concerning the question, I think that the future of crystallography will be the aformentioned multidisciplinarity and combination of methods, as well as the clarification of myriads of structures in nanoscale and molecular level. Of course large-scale facilities, including X-rays from Synchrotrons and ultrashort & brilliant X-ray flashes from XFELs, will intensively contribute to the development of the new era in Crystallography. Thus, in my opinion, bright future and many jobs in modern Crystallography...
One of my Mentors at Rutgers, Dr. Thomas Tsakalkos, used to paraphrase his teacher Andre Guinier - " if you find smoke in the reciprocal space then you will find the cigar in the real space". Many in crystallography have not yet grasped the import of this thought yet. So, there is still a lot of room to improve and get better for crystallographers and crystallography.
http://www.flickr.com/photos/85210325@N04/10242907544/
Crystallography is dying (partly, really!), because (some) crystallographers too often behave in the way the cliche would expect them to behave. For instance, by overemphasizing group theory and symmetry in general, when they themselves even lack the mathematician's knowledge of groups (seen in the far too narrow concept of "crystallographic groups") thereby neglecting all the other structure formation ideas around there (which physicists and even biologists appreciate far more than crystallographers). Thus, in my opinion, crystallography should become a "science of structure" in the most general sense, even if "crystals" are not involved at all. Then it will be easy to show that it is not a dead or dying science.
A simple statistical test - see the number of data deposited in the Cambridge Data Base, Protein Data bank and Inorganic data base over the last few years! If the pulse is strong and felt clearly, should one worry whether the patient is dying?
Regarding Soft Matter materials and structure research by scattering methods I am not afraid that the scattering methods will become less important. In structure analysis of well ordered nicely crystallized materials methods have largely developed towards routine analysis but there are so many open and challenging questions on less ordered soft matter based systems and in particular their dynamical structure evolution that I cannot see that scattering methods become obsolete in future. Concerning the importance of diffraction methods in particular in protein crystallography the increasing number of solved protein structures in my opinion is just the clear indication that these methods have become an established standard tool in molecular sciences that no one would like to miss. I won't attend the funeral at all.
I do not think that crystallography will succumb to automation and modern computer applications. Growing crystals of rare elements $ its compounds will find its use in modern technology., Its application in cloud seeding $ artificial rain formation It will have a good future
I can understand Pieros point of view quite well. Crystallography is a science which is much bigger than diffraction (of nano or macrocrystals) or scattering, and already now I have the feeling that an entire generation is missing who understands the fundamentals of crystallography. In so far I am not that optimistic, although I am convinced that a re-discovery of crystallography will happen when "nobody" understands anymore the link between theoretical fundamentaly and background. I observe more and more specialisation where the connection of the different aspects of crystallography are lost, and the available and certainly advanced tools are only applied (with only a limited or no understanding). But Piero already asked the correct question: Who shall programme all the required tools when nobody is available anymore? I was working for a company which really needs some well-educated people in (geometrical) crystallography, but until now - after some years and writing letters to all german-speaking institutes teaching crystallography we did not get any respond. I am not sure whether there is anybody of the new graduates able to draw (or derive mathematically) a simple orthorhombic space group. We should try to maintain this intuitive understanding of symmetry, but it becoomes more and more complicated in a time of Apps where you obviously get all delivered free to the door.
Right you are Gert! I've virtually been out of the field from 1988 to 2005 when I re-entered. I'm yet to see significant differences in the state of the art between the two periods in use for XRD. Still a Jurassic Park! Astounding! Especially when I observe the archaic technology that the present day top echelon of XRD/Crystallography equipment manufacturers are continuing to peddle. A Zero Dimension (0D) point/scintillation counter in 2013? Give me a break! Just think about it. The entire powder diffraction data-base that we use presently could be out dated. These ID diffractograms may have to be obtained and saved in a 2D, 3D or more-D format for the future. I see a huge opportunity and will take advantage! Especially, because the existing old equipment may be re-tooled easily!
GE Diano/Phillips http://www.flickr.com/photos/85210325@N04/8001169005/in/set-72157632729013664
Rigaku: http://www.flickr.com/photos/85210325@N04/8001167498/in/set-72157632729013664/
Bruker: http://www.flickr.com/photos/85210325@N04/8001160995/in/set-72157632729013664/
Panalytical: http://www.flickr.com/photos/85210325@N04/8001095415/in/set-72157632729013664/
T-ReX (LOL!): http://www.flickr.com/photos/85210325@N04/8001105680/in/set-72157632729013664/
I encourage all to acquire, promote and master the fundamentals with this classic as your contribution to exploiting the myriad of XRD methods:
X-ray Diffraction In Crystals, Imperfect Crystals and Amorphous Bodies by Andre Guinier. 1962 - Great book! I continue to read and learn.
Gert! We are building an awesome team (New Jersey & Bengaluru) with the specific expertise that you have mentioned and are excited about the results of the synergy so far at Onsight Technology USA. A lot of room to improve & grow!
Please feel free to explore and join our group in LinkedIn as well and help propagate the knowledge of XRD principles and methods in practice. Here's a good example of a technical poll/discussion:
http://www.linkedin.com/groupItem?view=&gid=2683600&item=ANET%3AS%3A218925637&goback=%2Egde_2683600_member_5800905620634755076&trk=NUS_RITM-title
http://www.flickr.com/photos/85210325@N04/10515372183/
Crystallography is very wide and critical field, specially single crystal or powder one, the future is like any branch of science, it should be improved to solve more complex structures.
Piero,
glad to see that you brought out the problem here. I have discussed about this topic with a few people in the past months (some involved in IYCr 2014 as well). I think the answer is really in the question that Walter placed: "what is crystallography?". For sure the "old" crystallography is long time dead. Sad, but most people actually "solving" protein structures (they believe they're the true crystallographers) don't even know crystallography. This is mainly due to the fact that the number of academic courses in crystallography is reducing and the things to discover, from a scientific point of view, are limited. Most of the historical groups are being shut down (people retire) and there is no replacement. I see a desolated land when I look in my field (microstructure and stacking disorder): in some cases people, software and know how are not longer available and you have to restart from scratch if you want to give some (needed) advancement to science. The Universities (and the EU for instance) have the same short sight and belief: "crystallography is something known". No matter if some issues are still not sorted out or if some crystallographic problems are of huge scientific or industrial importance, but a "crystallography group" or a research in the basics is not attractive. That's the hard law of science nowadays.
So my opinion is that "applied crystallography" has replaced (or is replacing) "basic crystallography" because of convenience. And to be attractive (we need funds to survive), it is given different names or different goals. After all, graphene needs crystallography, energy materials need crystallography, MOFs need crystallography, computational chemistry needs crystallography... if you have a TEM you need a crystallographer and it seems electron crystallography is one of the new frontiers for the hardcore crystallographers...
So, Piero crystallography can't probably survive alone, but it is also true that several disciplines can't survive without it.
Matteo, I have no proof but I can imagine that fundamental crystallography was never the best way to get somes fundings, it was mainly applied crystallography which enables to get a bigger budget, to have more students, and to do some fundamental research. Therefore to me it sounds like a weak explanation for a less effective crystallographic educatuion. Is there any science around the world which can claim that all is known and one can now finish scientific work? Although crystallographic only "describe" crystals or try to optimize the description of crystalline materials. But also history is doing this, and we know that it is important to learn from history and maybe to change sometimes the point of view in order to recognise more or see some global connections which havn't been discovered before. How crystallographers can do this and can reduce their competence to a simple service for some other people who claim they are doing crystallography? I studied crystallography for five (!) years and by god I am far away from saying that I know all about it. There are people who are chemists and physisists which have certainly a very huge knowledge about their topic, but frankly speaking I cannot believe that they are better educated the someone who was studiing crystallography not as specialisation. I don't want generalize this, there are definitely well-educated specialists coming from chemistry, physics, or mineralogy, but from my opinion they cannot compensate the entire overview you get teached over 5 years. They are specialists in a very special part of crystallography. However, all these specialists are not linked anymore. They do not speak the same language. Even on conferences they are very specialized, they are mixing basic crystallographic terms like lattice and structures. How do you think this will work in future? At the moment we still have guys like Sven Hovemöller...but in ten twenty years?
My recommendation is: don't give up and don't follow some trends which are popular at the moment, simply because of the lack of money. This was always existing. I guess, it is simply easier to get some money for crystallographic applications...and programmes like Rietveld analysis or single crystal structure analysis are now mostly working automatically. And if a data set is not solvable...they simply start a new one or replace the crystal without a deeper inspection, why this happens. Anyway, I don't want critizise here anybody. I am sure that all of you do their job with a high responsibility. But crystallography is not dead, only because a few people want see this or obviously don't have any visions anymore...
Bright!
I am an organic chemist turned supramolecular chemist. Transformation started around 1990 when I realised many problems associated with conventional drug development. From medicinal chemist angle a compound normally has to complex with a receptor to show useful medicinal properties. At that time not much was known about arene-arene or pi-pi interaction. Attractive interaction between two arene residues is known as arene interaction and occurs widely in DNA/RNA, proteins and drug-receptor complexes. In 1995 we first published a simplest propylene linker model based on pyrazolo[3,4-d]pyrimidine which is isomeric with purine system of two DNA bases well known for stacking (arene interaction). Since then we have published about two dozen papers dealing with various aspects of arene interaction especially intramolecular for controlling conformation. All these papers, published in collaboration with X-ray crystallographer, have one or more X-ray structures to demonstrate role of intramolecular arene interaction for conformational control. Needless to say that all this was not possible without extensive use of X-ray crystallography, as using proton NMR alone was not sufficient. Arene interaction is just one of the many noncovalent interactions, whose understanding is must for new drug development.
I believe that the future of X-ray crystallography is bright and quite useful to medicinal chemist and organic chemist in understanding of any process that depends on noncovalent interactions. Crystal engineering is another area that demands extensive use of X-ray crystallography.
Friday Evening Discourse at the Royal Institution, Professor Stephen Curry - See more at: http://richannel.org/seeing-things-in-a-different-light#!
Originally posted by Iuliana Cernatescu, PhD in the LinkeIn Group "X-Ray Diffraction and Scattering Techniques":
http://www.linkedin.com/groupItem?view=&gid=3614857&type=member&item=5802956386895683584&qid=b1a8d0e7-e2ab-4dff-9044-1c9700d3ff8c&trk=groups_most_recent-0-b-ttl&goback=%2Egde_3614857_member_269111613%2Egmr_3614857%2Egde_3614857_member_5802956386895683584%2Egmr_3614857
http://richannel.org/seeing-things-in-a-different-light#!
I beleive there are two areas that surely will become very important: one of them is time resolved XRD for its importance in biomolecules machanism, temperature control allows to follow mechanism of reaction, but is only possible trough pulsed methods and Laue solution. The second area is orbital fitting to electron density, these experiments require lots of data but allows to visualize H-bond such those in DNA, for the moment. These two areas are of great importance to biochemistry and bilogical chemistry of diseases.
Victor! "time resolved XRD for its importance in biomolecules machanism, temperature control allows to follow mechanism of reaction, but is only possible trough pulsed methods and Laue solution"
Dr. Rober E. Green Jr. of JHU, Baltimore and his group has done some pioneering work with 2D real time XRD imaging and pulsed X-ray generators. There are desk top pulsed X-ray generators available, since the 1980's, with Synchrotron comparable intensities in short bursts! These are presently used in radiographic applications (Military). The pulse rates are comparable to the frame rates available for real time high resolution 2D X-ray detectors. So, the technology exists now to execute your wish!
http://www.flickr.com/photos/85210325@N04/10659886546/#!
Gert, I don't give up, don't worry. And even if I am not officially a crystallographer, I am running and submitting projects not just on applied crystallography but also on basic one. I hope more people will go on like this and that institutions will understand what crystallography is. It's absurd that we have an international year of crystallography, but there is nothing related to it e.g. in the ERC (European Research Council) panels. Check the number of Nobel prices in crystallography (not considered) vs those in all other topics there (e.g. http://erc.europa.eu/sites/default/files/content/Panel-descriptors_ERC-2013-AdG.pdf).. and start wondering.
In any case I totally agree (and that was part of my criticism, as you see), that most of those pretending to be (protein) crystallographers are actually just highly specialized biochemists (no offense here). It is easier to look for another crystal rather than understanding why the current pattern does not index automagically... but, in the end, if number of papers or impact factor is the way of weighting research, this is the winning strategy, right?
I think we are all looking for simplifications. In so far it is an easy but only statistically meaningful way to look for impact factors or number of publications. How long somebody needs to publish a crystal structure, and how much time you are busy to determine the depth profile of residual stress distributions for a group of materials after shot peening? Number of papers, and even impact factors are limited opportunities to judge about the worth of a publication. But this entire scientific race for higher impact factors etc. shows us something about ourself...about our real driving force.
Nevertheless, there were, there are, and there will be always technocrates who need to judge about scientific work using a simple number, or even cliques to decide about budgets an fundings. I only want to point out that this miserable current situation does not mean that crystallography is dead. It is simply contineously changing...similar to the nature. We can do something or we can leave it. It is only a shame about all this knowledge and the time which will be necessary to be reactivate it again. Crystallography will make its way also in future. And the more complicated structures or anisotripic distributions (I totally missed these important parts of crystallography in this discusion) will be the sooner crystallographers will be requested and universities will start to teach them again. We can be part of this development, or one of the next generations will do this (because we personally believe that it is perhaps not (financially) beneficial for us) :-). The easiest way is often not the best one but promises the fastest success.
I glanced through this discussion looking for aperiodic crystals. I haven't found any (it's a pity I couldn't use the "search" feature). This phenomenon (the tiling problem discovered theoretically by Penrose, then confirmed by Hechtmann), implies that somehow atoms must "know" it's entering into an aperiodic crystal. In the case of ordinary crystals it's basically the atom is the key and the binding site is the keyhole, it fits in. It's a local affair. However, in the case of aperiodic crystals it has to be non-local - the atom, the "key", has to sense a "keyhole" that encompasses the whole crystal. A field that deals with problems like this has to have glorious future, right? My question is - is my reasoning about non-locality correct?
Great insight by all! Even if the question itself is basic the answers surely indicate the talent pool and knowledge base available on RG. Age of participants does not dull knowledge. It only enhances the perception. Keep sharing!
Knowledge is one of those among wealth that keeps growing as you give it away! The more you give the more you get!
http://www.positivelypositive.com/2013/07/18/the-more-you-give-the-more-you-get/
Gert! "I studied crystallography for five (!) years"
That is impressive! Where did you have the opportunity for 5 yrs. of formal crystallographic education? That sounds like an entire undergraduate course schedule in any University. There ought to be more of such opportunities available.
My background is Metallurgy & Materials Science. In the 10yrs of this education, I barely remember about 5 courses I took in this subject. I had to learn many of the principles on my own in the XRD lab spending countless hours observing real time 2D XRD images from a myriad of materials. Mostly materials of commercial relevance. Powders, films , foils, fibers, bulk and large single crystals! Simple crystallographic groups compared with the more complex groups prevalent in geology. These days with pharmaceuticals, the opportunity is even better to use crystallography and its principles to unlock Nano structural details practically.
Robert! "aperiodic crystals"! Interesting Segway. More to learn. This would be relevant to biological crystals and some of the other more complex molecular structures. Right? It would be exciting to observe such materials using Real Time Bragg XRD Microscopy. Can't wait to get my pudgy hands on this type of material. Any volunteers?
Your description is a little asymptotic due to my present lack of knowledge. I resolve to learn this aspect better, soon. Thanks for cracking the window open.
http://en.wikipedia.org/wiki/Quasicrystal
Ravi, this was in "old socialist" time in GDR. The Humboldt University and the University in Leipzig teached Crystallography as separate discipline of study for about 12 students per year :-). I have to admit that it was a really inspiring time. Mathematics and Physics mainly together with physisists, chemistry on the chemical department. Special mathematics, geometrical crystallography, physical crystallography, quantum physics, crystal defects, crystal structure determiation, chemical crystallography, phsyical-chemical crystallography, light and electron microscopy, universal stage application (indcatrix, orientation measurements etc), reflection goniometry, X-ray diffraction, petrolography, phase diagrams etc we heard in our own institute. It is really a pity that this entity of crystallography is mainly lost and often reduced to crystal structure determination.
OK Gert! Let us make the difference without the "old socialist" paradigm. Let's do it for the obscene "profit" motive or for just the "love of the science". Once we create a motive then it will rejuvenate. The objective of all science is its ultimate application to alleviate the "human plight". I see enormous potential for applying nearly a century of knowledge utilizing modern tools and techniques. Not much has changed fundamentally in what we know about XRD methods since the Braggs. Every one of the book recommendations here is one of the well known age old texts. Here is a section from Andre Guinier's book that captured my attention:
X-ray Diffraction In Crystals, Imperfect Crystals and Amorphous Bodies by Andre Guinier. 1962 - Great book! Worth acquiring for your XRD collection.
(pp. 162-163) 6.3.5. Comparison between the Photographic and Counter Methods
"It is obvious that the Geiger Counter and the ionization chamber have the advantage of precision and sensitivity. They alone permit a quantitative study of scattering. However, point by point measurements in reciprocal space are lengthy, while the photographic method gives directly a picture of the scattering in a single experiment over a large surface of reciprocal space. The resolving power of the film is excellent. Thus, sharply defined scattering regions, for example on rows or on planes of reciprocal lattice, show up very clearly on photographic film but are difficult to detect with a counter.
Let us note also that the counter is "blind". In many cases inaccuracies in the setup produce stray scattering which is easy to detect on the photographic film but which can spoil a series of experiments made with a counter.
The two methods are therefore complimentary and it would not be advisable to neglect one in favor of the other. The photographic method is admirably suited to the qualitative exploration of an unknown pattern, since one can then find totally unexpected phenomena. The counter is necessary for quantitative measurements on a pattern which is already known qualitatively."
This was printed in 1962. This has to be considered in light of the present day 2D detectors that combine the benefits of the counter & the film in one. These writings indicate the present day inertia of moving from the 0D to the modern 2D detectors. The spatial "blindness" of the 0D scintillation counter/detector is the principal reason even experienced experts using XRD are ambivalent about the conventional linear XRD data/results using the 0D detector.
3 / 0 · 55 Answers · 993 Views
Piero! You may be able to improve circulation of this question to a larger RG cross-section by changing the topics "up top" every now and then.
Besides, there are a lot more than 3 members that have contributed great ideas. I suggest each contributor at least check off the "up/down" vote "up top". In my opinion, if you took the time to comment then it should be an "UP" vote in self-edification. It is a certitude that you wasted neither your time nor your intellect.
As Rodney Dangerfield said to a morose looking individual who told him that he was happy, "then inform your face" (smile). See example below (only jesting)!
http://www.flickr.com/photos/85210325@N04/10221987094/
I realize the expertise of RG members interested in this discussion is exceptionally high by your scores, writings and profiles. So I'm going to dare to elicit your help with the analyses of some of our real time experimental findings from BNL and AFRL recently acquired. Please feel free to jump in help me out.
1.https://www.researchgate.net/post/What_are_the_causes_for_ASYMMETRY_in_the_Bragg_X-ray_Rocking_Curve_Profile_RCP_for_a_symmetric_004_GaAs_reflection
2.https://www.researchgate.net/post/X-ray_Rocking_Curve_Analysis_of_Super-lattice_SL_Epitaxial_Structures_What_are_some_of_your_practical_experiences_with_this_method
You can knock me down a couple of notches if needed, no problem. But, I'm finding near perfect match with theory. I'm unable to find similar results elsewhere in literature yet. Am I the only one? There's got to be someone else besides me in the world that has thought of this. I'll post this in a few other discussions with different set of experts. Hopefully we could bring together a "Master Mind Group"!
Theory meets Experiment!
http://www.flickr.com/photos/85210325@N04/9430820747/in/set-72157635172219571
See answers from a lot of crystallographers in Z. Kristallogr. 217, 7-8, 2002.
http://www.degruyter.com/view/j/zkri.2002.217.issue-7-8-2002/zkri.2002.217.issue-7-8-2002/zkri.2002.217.issue-7-8-2002.xml
Armel! Not sure how to navigate this link. Any chance you could send a PDF file. I'll try again. Thanks!
Here's the error message: "An error has occurred in the application. Please contact support. Thank you for your patience and understanding."
Firstly it was not working but now I can use it. Possibly redirect from RG is not doing well with such link.
I studied crystallography at the beginning of the decade of the years 60 comprising the basic part that indicates the Dr Gert Nolze and apart methods of X-ray crystallography. A complementary course of structure determination methods seem right, but eliminate the course of basic crystallography that indicates the Dr. Nolze and impar only the methods of crystal structure determination, no
studied crystallography at the beginning of the decade of the years 60 comprising the basic part that indicates the Dr Gert Nolze and apart methods of X-ray crystallography. A complementary course of structure determination methods seem right, but eliminate the course of basic crystallography that indicates the Dr. Nolze and impart only as course the methods of crystal structure determination, no
Crystallography, which is an Applied Chemical and Physical Crystallographers, using the capabilities of the technique to chart new, exciting and relevant developments. It can be used for both single and powder samples in addition yo characterization of several constant in companion withelectron microscope and elemental analysis .It really will be the most important techniwue used all over the world.
Wish you all happy crystallography year 2014....Welcome Crystal year IUCr 2014.
This is some "ground breaking stuff", in my opinion. I'd appreciate to hear your erudite unfiltered opinion. If you prefer, you may email me at [email protected]. This is basic research into crystallography to the n-th degree. Real Time Bragg XRD Microscopy!
This is my first attempt at directly uploading a PDF file to any RG discussion. Let's check if it is satisfactory? Made it!
Only few places in the world such technology is readily available for install in any existing diffractometer with minor modifications. These are New Jersey USA and Bengaluru/Mysuru India as of January 10th, 2014. The instrument is certainly available for live demo in these locations and their immediate vicinities.
P.S.: I'm beyond embarrassment and do not take offense to critique. I only learn from your helpful suggestions every time. Thanx!
One of the recent trends in modern crystallography is in developing techniques, instruments, and software which allow real technological materials to be measured in-situ and in-operando. To properly understand the properties and kinetics of most materials one has to be able to measure samples that are between single crystals and powders. It has only been in the last 15 years that such techniques have matured to allow new science to be done in furthering the understanding or subjects as diverse as texture formation, grain growth, crack propagation, Fuel cells, hydrogen storage, nucleation, recrystallization, domain switching, etc... Because these techniques are fast, non-destructive, and provide a high resolution 3D map of polycrystalline microstructure it is ideal for testing and improving modeling of basic materials science towards developing more realistic models for predicting microstructure development. The information one gets would be similar to 3D EBSD (which can be done tediously and destructively by serial sectioning) with the added benefit of higher resolution in reciprocal space (and in 3D reciprocal space) which allows additional information such as the local elastic strain tensor, and structural refinement of 1000's of grains simultaneously within a polycrystal. This will also have an impact on protein crystallography, since often 99% of the work is trying to form a single crystal. Obviously the ability to solve a protein structure with a polycrystal has the potential of transforming the standard way in which protein crystallography is performed.
APLAUSE! Go Larry Go! It took us only a century to figure out what the Braggs figured out. History does have its value after all! Watch your toes!
With the advent of the modern day high performance 2D real ime XRD imaging devices, the potential is boundless for those who are open minded.
BTW I like the ability that RG has provided for fonts, pragraphing and super/sub characters. Cool!
https://www.flickr.com/photos/85210325@N04/10221987094/in/set-72157645018820696
Dear Dr.
This paper is useful
http://www.ncbi.nlm.nih.gov/pubmed/24372145
http://www.iycr2014.org/__data/assets/pdf_file/0010/78544/220914E.pdf
From the crystals obtained by mineralogists, chemists and scientists in the field of solid materials the crystallography contributes to the progress of experimental science.
By careful design of series of novel organic structures followed by crystallography role of weak noncovalent interactions in conformational control can be determined which is very difficult by other means.
- Badges
- Science method
- Similar topics
- Methodology
- Crystallography