Dear Chemgrrl et al:
When use XRD to characterize CNTs, is the "d" in Braggy Eqn. the diameters of CNTs?--Lin
Can you answer these questions for me???
thank you for your time
gracee***
None of my business really, but looks neutral to me. 12.14.174.162 04:52, 25 June 2007 (UTC)
You can determine the 3d structure of -pretty much- any molecule using x-ray crystallography. Could be small molecule or really huge molecules like proteins. All you need is crystals of that molecule really. -Ert
It would be helpful if there was a section on methods for determining structure (eg. Laue methods, Debye-Sherra method, etc.). I'm just researching it so I don't think I'd be much help atm.
Hi everyone. I am considering doing a fairly major edit of this page. I do this (biological crystallography) for a living and am more than happy to spend some time putting more about it in the public domain. This is fairly complicated area, and I am happy to take any and all suggestions about it. I think there is a fair argument for giving Biological Crystallography its own page, but for now I'll do the edit in page. I was thinking about doing stuff under the following sub-headings
Let me know what you think... Bassophile 20:55, 9 February 2006 (UTC)
Hi The Spirit. I'd appreciate any assitance/comments/criticism you have... I think it's a little patchy at the moment. I'm trying NOT to include too much nasty theory, but I suppose some is inevitable. I'm also trying not to duplicate what has already been done elsewhere. There is a nice section on unit cell which includes a good introduction to symmetry etc, which is why I've left that out. I've also not gone into Bragg's and Laue's laws/conditions as they too are covered elsewhere. Let me know what you think so far.
Cheers, Bassophile 15:30, 14 February 2006 (UTC)
A little discussion about your rather major changes to this page would be appreciated! I would argue that the crystallisation and data processing of small molecules and the crystallisation and data processing of macromolecules, whilst being superficially similar, are sufficently different to merit their separate sections, as I had originally laid out. I suggest we combine our efforts and deliniate Small molecule and macromolecular crystallography whilst highlighting the differences and similarities between the two disciplines... Bassophile 20:20, 28 March 2006 (UTC)
I removed the notice about merging this article with crystallography. That article clearly discusses other techniques beside x-ray. It is not clear to me that they need to be merged. Rmhermen 21:01, Nov 14, 2003 (UTC)
Yes, crystallography addresses additional techniques, but those others are also based on diffraction from crystals and on the construction an image by fourier transformation, and so a lot of the explaining that needs doing for one of them needs doing for all of them. I think we should have one good explanation of the commonalities in one article and links to specific articles just for the fine points, such as that a lot of X-ray stuff is going on at synchrotrons and figures in big international proteomics initiatives. 168... 21:51, 14 Nov 2003 (UTC)
The article states that usually one works at 100K. Has it always been this way (and if so, why)? I'm reading an Acta Cryst. of 1976 and it doesn't mention the work temperature. It wold be very interesting to me to know whether I should assume that the determination was done at room temperature or at 100K... Thanks :-)
No, rt was common until cryojets were developed in the 1990's. The use of low temperature significantly improves the data due to less molecular motion and disorder. Hokietiki@hotmail.com 22:38, 29 January 2007 (UTC)
Actually the advantage of 100K is more to do with radiation damage. See, for example, Garman and Schneider 1997. — Preceding unsigned comment added by 129.67.79.78 ( talk) 11:22, 4 May 2013 (UTC)
I updated the link to resolution to Sensor resolution. This might have needed to be a link to Optical resolution. Feel free to change it if you have more insight in to this then me. -- STHayden 22:21, 6 August 2006 (UTC)
I think protein crystallography should have its own page (possibly redirected to from 'macromolecular crystallography') -- different refinement approaches, different ways of phasing, much more trouble with crystal growth ... Fivemack 15:55 21 September 2006
Would anyone like this:
{{User:Bassophile/UBX}}
Bassophile
13:46, 11 January 2007 (UTC)
It's not clear whether the article is about x-ray crystallography (generic field of study and family of analytical techniques) or about the analytical technique of single-crystal x-ray diffraction. It also seems that other methods such as powder diffraction are mixed up in this article. In my line of work few people would refer to powder or thin-film diffraction as "crystallography", whereas the single-crystal jocks call themselves "crystallographers". I have substantial experience in non-single-crystal methods and have started an alternative page x-ray diffraction to clear this up. Irene Ringworm 16:43, 28 February 2007 (UTC)
My understanding is that reliance on fourier transforms in diffraction instrumentation is really as a more modern computational tool. Before advent of computers, who used (or would want to use) fourier transforms to assess a crystal structure? People made Ewald spheres with simple algebra, which was every bit, if not more, "physical," relative to the transform (and contrary to this article, calculations in real space are no less "physical" than those in reciprocal space - its a matter of the more effective tool for the circumstances). It's like saying atomic spectroscopy, born out of diffraction-grating spectroscopy, is based on Fourier transforms, simply because they have, in recent years, found application as very convenient, high-resolution, computational tools.
Because the present-day numerical tools accurately transform the output of the instrument does not make Fourier necessary, let alone central to the historical foundations of the field, or the evolution of its fundamental physics. Wikibearwithme ( talk) 20:52, 18 November 2015 (UTC)
I would call the ribbon structure in the lead image a molecular model rather than an atomic model. Agree? ike9898 21:41, 8 May 2007 (UTC)
The following suggestions were generated by a semi-automatic javascript program, and might not be applicable for the article in question.
between a number and the unit of measurement. For example, instead of 3 mm, use 3 mm, which when you are editing the page, should look like: 3 mm.
[?]You may wish to browse through User:AndyZ/Suggestions for further ideas. Thanks, Wim van Dorst ( Talk) 22:01, 9 May 2007 (UTC)
Can someone provide a reference for "Twinning often occurs when the unit cell has a net electric dipole moment (ferroelectric crystals), because of a subtle interaction between the dipoles of the bulk crystal with polarization charges expressed on the crystal's surface."
Bassophile 07:43, 22 May 2007 (UTC)
Hi all!
The article would benefit from a lot more pictures, don't you think? I'll try to make schematics for the sitting/hanging drop methods and for the kappa goniometer, but my drawing skills are lame and it would be better to have real photographs. A photograph of a precipitate droplet might be nice, too. Images of the electron density at various stages of the phase refinement would also be great, perhaps as a mesh surrounding the final structure as a stick model? Any help would be much appreciated, Willow 14:45, 24 May 2007 (UTC)
This article implies that this technique is solely used for determining the structure of organic molecules and inorganic compounds. However, x-ray crystallography is the science of using x-ray diffraction to understand the structure of crytalline materials, not of molecules per se, and as such includes its use as a tool for geologists looking at the crystal structure of minerals. Is there some reason I am missing that this article has declared the technique to only be a tool in the life sciences? KP Botany 18:44, 27 May 2007 (UTC)
Whether or not I include anything, the article can't be written as if it is something that is not, ie, the entirety of x-ray crystallography, when it is not actually about x-ray crystallography, but only part of it. It's like writing an article about radio waves and labeling it the electromagnetic spectrum. I will tag it for now. KP Botany 17:20, 30 May 2007 (UTC)
Bassophile, while I'm happy you're so knowledgable on the subject that you can write on the fly, I can't. My concern is that readers coming to the article as it now stands will think that x-ray crystallography is a technique for studying organic molecules. It isn't, it is the science of looking at the structure of crystals, some of which are organic, to learn their atomic and/or molecular arrangements. As long as there are sentences like this in the article, "X-ray crystallography is used in chemistry and biochemistry to determine the structures of inorganic compounds, DNA, RNA and proteins," which are clearly false, it has to be tagged to warn readers. Although I've done some x-ray crystallography, it has been quite some time, and I am unwilling to write on the fly about something so complex that I haven't done in a while. When I get my facts straight I will add to this article. You might consider renaming this x-ray crystallography (biological) in the meantime, if you simply don't know anything about the materials aspect, or don't have the inclination to add anything about it. KP Botany 18:15, 31 May 2007 (UTC)
Willow, the real problem now is the article is entirely geared towards biological. I see the introductory paragraph has been changed, but from there it boldly goes on as if the article is all about the biological. I think making it accurate is more important than hurrying up, and, imo, the best Wikipedia editors are those who have lives outside of Wikipedia, so please enjoy your time with family then add material as appropriate. I know people don't like tags like this, but it is important to alert readers that there are issues with article, so they know to be careful about what they take from the article. I think the article should be general about x-ray crystallography, as that is its title, and other articles should deal with the specific techniques. See Electron microscope and Transmission electron microscope and Scanning electron microscope for a good idea of how it can be done. It would be wonderful to get a good series of articles on Wikipedia for the layman on these topics. KP Botany 18:53, 1 June 2007 (UTC)
(reset indent) I've gone over the article again. Please bear with me, if I appear biased. I can only speak for my own experiences. I have absolutely no experience with protein crystallography, and I have no knowledge of the history of crystallography beyond Bragg's law. My experience is as an inorganic chemist - the use of X-ray crystallography to determine the connectivity and the solid state conformations of organometallic compounds.
These are my suggestions.
With regard to #1 and #2, I'll try my best and find some information. Perhaps someone can help with #4. -- Rifleman 82 14:09, 5 June 2007 (UTC)
If there is a lot more information on protein crystallography, perhaps it should be split into a separate article " protein crystallography", which discusses the finer points. The broad strokes can remain here. I.e. diffraction theory, sample prep, data collection and analysis. -- Rifleman 82 14:16, 5 June 2007 (UTC)
130.88.210.108 14:09, 3 July 2007 (UTC)
It still looks very unbalanced as there is a lack of pictures, references and external links for non-biological applications. Even the history section is dominated by biological developments, leaving a couple of short sentences for the early history. GB 03:25, 5 July 2007 (UTC)
"Scientific pre-history of crystals and X-rays" is a bad title for the section. "Pre-history" specifically means before written records, and "Early scientific history" would be more accurate. —Preceding unsigned comment added by 164.67.237.80 ( talk) 02:33, 8 November 2008 (UTC)
Hey there small molecule lovers! I have re jigged the phasing & history section to pay a little more homage to the elucidation of small mols - I even made and dropped in a picture of Penicillin for your enjoyment and delight - I am content and happy to do some more tweakage in most sections, but I am afraid I am not au fait with small molecule crystallisation (drop in it something volatile and leave it to concentrate & crystallise???) or SM data processing, beyond the direct methods stuff. I suggest that someone with SM expertise needs to look at and point out some basic points that need inclusion. However, here are my thoughts:
Willow - FANTASTIC WORK - If I'm stepping on your toes, let me know - I tend to be a little sporadic as my wiki-time can be variable.
Keep up the work, editors! Bassophile 11:02, 13 July 2007 (UTC)
As promised, I've returned to work on the History section and would be grateful for constructive criticism and specific suggestions, especially from editors who still feel that the article is unbalanced. I added a bit of chemistry today and will be adding some physics over the next week or so. It would be helpful to know which results from other fields should be added to our description of X-ray crystallography. Once the content is more-or-less agreed upon, we can add all the inline citations and figures. Thanks for your help! :) Willow 21:44, 30 August 2007 (UTC)
I'd like to come up with a list of Figures that might augment the article. Here are some of my initial thoughts; please give me your ideas on these, and feel free to add more!
I realize this article is getting long and detailed. However, I'd like to get a complete picture of the field before we fork off daughter articles. Thanks for your patience! :) Willow 16:55, 31 August 2007 (UTC)
Keep up the good work Willow! From the text books I have including the topic:
Graeme Bartlett 22:49, 31 August 2007 (UTC)
I'm not sure if the template is still necessary, but in any case it was misleading IMO. The template said "This article's representation of one or more viewpoints about a controversial issue may be unbalanced or inaccurate." IMO this is not a controversial issue, but only a matter of missing information and balance. I've replaced it for now with the {{ missing information}} template, which I hope will be more accurate and explicit. It says "Concern has been expressed that this article or section is missing information about: minerals and crystals that are not molecular/biological." -- Itub 09:01, 18 September 2007 (UTC)
I've noticed that the article is getting a bit long. The lead is longer than the recommended limit of four paragraphs (it currently has five slightly long paragraphs), and some parts of the article could probably be split out and summarized. I think the easiest one to split out would be the history. -- Itub 16:07, 21 September 2007 (UTC)
The introductory section of this article is incorrect. X-ray crystallography isn't about the "beam of X-rays being deflected by the crystal." That's what all this nonsense about lattice planes, unit cells, diffraction patterns and the like is about--x-ray crystallography uses the atomic arrangement of a crystal, not the macrostructure. KP Botany 22:42, 22 September 2007 (UTC)
Wikipedia:Talk page:"Article talk pages are provided for discussion of the content of articles and the views of reliable published sources. They should not be used by editors as platforms for their personal views." Nor for your personal opinions about me--these can go on user talk pages if they are related to a Wikipedia issue, otherwise they don't belong here period. It's always nice to see editors working so hard on an article that they have the time to use an anony IP to get in a personal attack. I suggest spending the time reading up on x-ray diffraction, instead. KP Botany 17:49, 23 September 2007 (UTC)
Wow. KP Botany 17:49, 23 September 2007 (UTC)
The talk page stands as it was when I put the disputed tag back. You have not dealt with the issue that caused the tag to be placed there. Please do so by putting a general introduction into what x-ray crystallography does and how it does it into the article before removing the tag again. KP Botany 02:04, 24 September 2007 (UTC)
It's not semantic hair splitting when the fact is crystallography is based upon the relationship between the atomic spacing and the wavelength of x-radiation. And it's bothersome to me that the editors of this article can't seem to grasp or deliver this idea to the audience. A mirror delivers a reflection that can be seen with visible light, understanding a mirror image can be accomplished through simple optical theory without ever getting to the atomic level. X-ray crystallography's foundation depended upon understand the relationship between the lattice structure of a crystal and the wavelength of x-rays. This is NOT semantic hair splitting, this is the underlying theory that directly led to the field. KP Botany 01:32, 27 September 2007 (UTC)
The present article, though we are calling it X-ray crystallography, is basically talking about single-crystal X-ray crystallography of biological molecules. I think it should not be too much trouble to fix up the naming later, and it may not be necessary to adjust the scope. If powder diffraction is considered an important topic, I think it can be handled in a separate article. There should not be too much duplication.
I spent some time looking over one of the cited references today, Glusker, Lewis and Rossi (1994), Crystal Structure Analysis for Chemists and Biologists. Their main distinction was between small molecules and large molecules. They give only a small amount of coverage to powder diffraction. They do NOT make a big distinction between diffraction studies of inorganic and organic molecules, so far as I can tell. Crystals are crystals. Their main focus (in an 854-page book) is not telling people how to do the studies, but how to interpret the results. They have a lot of chapters on applications, i.e., on what has been learned about specific structural problems by X-ray diffraction. They include some inorganic stuff in their application chapters. The point of my comment here is to show that adjusting this article to be sure it addresses small molecules and inorganic problems is probably not a large change. Also, the more recent books on crystallography that I found on the library shelf tend to use 'X-ray crystallography' as a term to cover MOSTLY single-crystal (non-powder) studies and MOSTLY larger molecules. So I don't believe our choice of names is wildly off. EdJohnston 22:14, 24 September 2007 (UTC)
One of the 'to-do' items listed above is 'Better treatment of the historical development.' For your consideration I offer the list of Nobel winners who made use of X-ray diffraction, or advanced the method. This could be made into a table like the one in Nobel Prize in Chemistry but it could be expanded to list one of the molecules that each one studied and its molecular weight. This would probably become a separate article if other people think it is a good idea. Here are the Nobel winners I identified.
NOBELISTS who worked on X-ray diffraction of solids:
Let me know if you think this is a good idea. We could try to fit the material into the present article but it's already quite large. Most likely it should be a separate article. EdJohnston 23:03, 24 September 2007 (UTC)
See the comment above by User:Irene Ringworm:
It also seems that other methods such as powder diffraction are mixed up in this article. In my line of work few people would refer to powder or thin-film diffraction as "crystallography", whereas the single-crystal jocks call themselves "crystallographers".
My own web searches gave results consistent with her comment. This suggests we might replace the following sentence:
WITH
Comments? EdJohnston 02:41, 25 September 2007 (UTC)
Willow expanded the caption for Image:Eden.png in the section X-ray crystallography#Model building and phase refinement.
An example of electron density for a protein crystal structure at 2.7 Å resolution. The heavy atoms of an arginine residue (upper left), a tyrosine residue (lower left) and a disulfide bond (upper right, in yellow) are highlighted. The intervening bonds represent the heavy atoms of peptide groups, while the smooth green tube running throughout represents a spline fit to the polypeptide backbone.
It's fine to provide more detail, but I'd lose the 'heavy atom', which suggests metals. Also if we are going to point everything out, perhaps numbers should be added to the diagram.
For comparison here's the original caption supplied by Bassophile when he made the diagram:
An example of electron density contoured at 1 sigma, of a crystal structure solved to 2.7 Å resolution. An Arginine residue (top left), a tyrosine residue (bottom left) and a disulphide bond (right) are highlighted
The version just preceding Willow's was the same as Bassophile's but with the 'top left' etc. parenthesized directions left out, which I agree are helpful for understanding. I tinkered a bit with new versions of the caption, but I think it's too hard for people to precisely figure out that picture. (There seem to be too many green tubes). Bassophile's caption (with the 'top left' etc included) I think is preferable. Note also there is a slight licensing problem with the image, in that Bassophile wanted to restrict use of the picture to just this article, which I think muddies the GFDL: Permission granted in Xray_Crystallography page - for other uses contact Author. EdJohnston 17:28, 26 September 2007 (UTC)
90.204.105.203 20:28, 11 October 2007 (UTC) That was me, btw Bassophile 20:31, 11 October 2007 (UTC)
It'd be helpful to have a clear roadmap to remove the "disputed facts" tag. I'm personally unaware of any incorrect statements in the present article, but I'm perfectly willing to believe that there might be some. It'd be nice to have them listed specifically, all in one place, here in this section, so that we can deal with them one-by-one and strike them from the list, similar to what's done at FAC. Once the disputed facts have been resolved, we can remove the tag. Willow 23:00, 28 September 2007 (UTC)
Likewise, it'd be helpful to list specific items of "missing information" that should be added to the article, so that we can add them and remove that tag as well. The spirits are willing, but the direction is weak — or at least Delphic. ;) Willow 23:00, 28 September 2007 (UTC)
I put these tags here for deficiencies in the article that have yet to be addressed. Namely, the article lacks an outline, a coherent understanable general explantion of the topic and development of the various uses of x-ray crystallography in a logical fashion, such as single crystals, chemistry, proteins, DNA. Don't start an edit war, and don't delete the tags just because chemistry is your area and it covers chemistry. X-ray crystallograpy is used extensively in the materials science industry for quality control, and has been used for this purpose for decades. To ignore it because you're a chemist is fine in your profession, but it's not fine for a Wikipedia article. KP Botany 01:51, 8 October 2007 (UTC)
Geeze, now I'm supposed to believe that hexamethylenetetramine is a rock or what? What is it with you and this article that you don't see how crappy it is, how disorganized it is, and how much it is missing? People will come here and think just like the lot of you that x-ray crystallography is something used by chemists and biologists exclusively. The article is a piece of crap. Good grief, one ionic crystal is used to describe the use of x-ray crystallography in all of materials science and geology?
Fine, the article is a piece of shit. Put all of you want it this way, and clearly our latest editor owns it enough to declare that a single inganic crystal makes the article perfect.
Keep the crap. KP Botany 14:04, 8 October 2007 (UTC)
This article should be moved to X-ray crystallography (organic) so everyone who thinks that the science is solely used by chemists to study organic molecules and by biologists can have the article that all of you so obviously want. Then it's fine by me to remove the tags. But without the tags, that you are removing without cleaning up this piece of shit, this article needs gone from its current title. Because you're lying to the readers--it's not about X-ray crystallography, it's about organic molecule x-ray crystallography. KP Botany 14:06, 8 October 2007 (UTC)
I will not edit a single piece of this article because editors do not want it to be anything other than an article on the x-ray crystallography of organic substances. That is not what x-ray crystallography is, a field limited to organic substances. It is a vast field that includes applications in metallurgy, materials science, crystallography, mineral identification, volcanology and other areas. The editors of this article have focused on minor points in the field without a clear outline of its historic development and the applications. The editor removing the tags is doing so without any knowledge of what is missing, or any concern for the quality of article that editors present to readers. As such is the case, I simply must concede ownership to him/her and his superior knowledge of wikilawyering to get the tags removed from this article at all costs. KP Botany 14:10, 8 October 2007 (UTC)
“ | The structure of diamond was solved in the same year, proving the tetrahedral arrangement of its chemical bonds and showing that the C-C single bond was 1.52 Ångströms. Other early structures included copper, calcium fluoride (CaF2, also known as fluorite), calcite (CaCO3) and pyrite (FeS2) in 1914; spinel (MgAl2O4) in 1915; the rutile and anatase forms of titanium dioxide (TiO2) in 1916; pyrochroite and, by extension, brucite [Mn(OH)2 and Mg(OH)2, respectively] in 1919; and wurtzite (hexagonal ZnS) in 1920. | ” |
Wow, I take a little vacation to work on Catullus, and everything goes crazy! Let's all take a little nap, shall we, and then return in a few hours to reach consensus?
I hope that we agree that this article is not a battle-field, nor a place to posture and needle one other; anyone wanting to do that is encouraged to find another outlet. We're all here to improve the article, right? And we can't do that unless we can articulate what's wrong with it; we need to diagnose its failings and find a cure. All we're asking for is a clearly defined set of criticisms that we can address.
Personally, I think the article is OK as is, and probably deserves its "B" ranking. It could be a lot better, though; I totally admit that. It suffers from weak flow in its writing and haphazard treatment of sundry topics. I wrote it pretty much single-handedly as part of the May Science Collaboration of the Month (that wasn't), and single-author works are notoriously stilted, especially when the author is no expert. The parts left over from before May are also pretty bad. Nevertheless, I've worked hard to improve the article, and it serves no good purpose to simply dismiss it as excrement. We would all do better if you could just find your voice and articulate exactly what facts are incorrect, what exactly you'd like to have added, how you'd improve the article, and what changes in its organization you'd recommend. Your previous comments, while clearly negative, have been pretty vague; at least they seem so to me. How can we fix the article if you won't tell us what's wrong? I know you can do better; please rise to the occasion now or tell us when you will be able to. Willow 16:00, 8 October 2007 (UTC)
"There has been some discussion of this in the past. Most small molecule crystallography seems to have be placed in powder diffraction (yes, I am aware there is a difference!). If you wish to add a section pointing out the differences between small molecule and macromolecular crystallography, such as more emphasis on direct methods, different crystallisation methods etc... go for it (be bold)! Bassophile 14:55, 30 May 2007 (UTC)" Bassophile 20:45, 11 October 2007 (UTC)
A 10 MB animated .gif, that is not even closely related to X-ray crystallography, takes ages to load and doesn't illustrate the concept much better than an ordinary image with labelled angles. However, I feel the image might be useful in an article on goniometers; it just shouldn't load on default. —Preceding unsigned comment added by 84.161.129.78 ( talk) 18:27, 1 March 2008 (UTC)
I'm just wondering if anyone would help spruce up the article on Laue equations? Thanks. Veritas ( talk) 01:12, 12 March 2008 (UTC)
Can anyone throw any light on this phrase please: "the John Wayne of crystallography" was the description given by Luzzati* of David Harker, the American X-ray crystallographer?
thanks,
nitramrekcap 17:16, 11 April 2008 (UTC) Talk:X-ray crystallography/Archive 1/GA1
"Walter Friedrich and his assistant Paul Knipping, to shine a beam of X-rays through a sphalerite crystal" is wrong. The crystal used was Copper(II) sulfate. This can be verified from the Max von Laue Nobel lecture. Avihu ( talk) 20:09, 17 February 2009 (UTC)
the title basically explains the question — Preceding unsigned comment added by Ammaralsheik ( talk • contribs) 17:09, 12 July 2011 (UTC)
Would anyone find it useful to include, near the 'Further Reading' or 'External Links' subsections, a new, compact subsection that lists the main scientific conferences in the field of X-ray crystallography (and links to the respective pages on wikipedia, such as Mid-Atlantic Crystallography Meeting ? Cmura ( talk) 02:01, 30 November 2010 (UTC)cmura
Portal:Xray Crystallography, a portal related to this topic, has been nominated for deletion. Your opinions on the matter are welcome; please participate in the discussion by adding your comments at Wikipedia:Miscellany for deletion/Portal:Xray Crystallography and please be sure to sign your comments with four tildes (~~~~). You are free to edit the content of Portal:Xray Crystallography during the discussion but should not remove the miscellany for deletion template from the top of the page; such a removal will not end the deletion discussion. Thank you. ··· 日本穣 ? · 投稿 · Talk to Nihonjoe · Join WP Japan! 17:11, 15 September 2012 (UTC)
Subject appears to lack sufficient notability for a stand alone article. Suggest folding it in with X-ray crystallography. Ad Orientem ( talk) 01:14, 30 January 2014 (UTC)
Can anyone tell me about the techniques of X-ray crystallography and how this technique can be used to determine the crystalline structure of solid substances such as sodium chloride. — Preceding unsigned comment added by 2.91.106.63 ( talk) 10:06, 14 September 2019 (UTC)
It is very odd to have this much focus on an institution in an article about a workhorse scientific method. Without disparaging Dundee, it isn't even the place where this X-Ray crystallography was invented. Maneesh ( talk) 02:57, 12 March 2021 (UTC)
103 link is dead
The lead section of this article is too long (as perhaps is the entire article). WP:Lead would have even an article this long only have a three to four paragraph lead while there are five paragraphs here. Too much is repeated from the lead in the definition section as well. Rmhermen 15:48, 24 September 2007 (UTC)
What are omit maps? I read a sentence about them in the article, but it's not explained, so I tagged it clarification needed. Please clarify, and thanks. Crystal whacker ( talk) 23:15, 5 October 2008 (UTC)
This article appears to be misleading because it ignores the work of Karle and Hauptman who won the 1985 Nobel prize for chemistry for their much earlier work on the recovery of crystal structures from x-ray diffraction data. —Preceding unsigned comment added by Jfgrcar ( talk • contribs) 04:19, 27 November 2010 (UTC)
The sentence: "The intensity of Thomson scattering declines as 1/m2 with the mass m of the charged particle that is scattering the radiation; hence, the atomic nuclei, which are thousands of times heavier than an electron, contribute negligibly to the scattered X-rays." is very not-intuitive even though it is presented as a matter of fact. It would be good to add something like "this means that large atoms scatters more intense than smaller ones". Also, the "intensity of scattering" is quite hard to comprehend anyway - does it mean that the waves scatter in a broader angle or that certain angles have a higher intensity of the out-coming waves?
Just above that sentence, the words "valence electron" and "free electron" are used - it would be nice, if it was explained, why there should be a difference in the interaction between the X-ray and those two different types of electrons in the material. OxygenBlue ( talk) 10:15, 14 January 2013 (UTC)
Dear Chemgrrl et al:
When use XRD to characterize CNTs, is the "d" in Braggy Eqn. the diameters of CNTs?--Lin
Can you answer these questions for me???
thank you for your time
gracee***
None of my business really, but looks neutral to me. 12.14.174.162 04:52, 25 June 2007 (UTC)
You can determine the 3d structure of -pretty much- any molecule using x-ray crystallography. Could be small molecule or really huge molecules like proteins. All you need is crystals of that molecule really. -Ert
It would be helpful if there was a section on methods for determining structure (eg. Laue methods, Debye-Sherra method, etc.). I'm just researching it so I don't think I'd be much help atm.
Hi everyone. I am considering doing a fairly major edit of this page. I do this (biological crystallography) for a living and am more than happy to spend some time putting more about it in the public domain. This is fairly complicated area, and I am happy to take any and all suggestions about it. I think there is a fair argument for giving Biological Crystallography its own page, but for now I'll do the edit in page. I was thinking about doing stuff under the following sub-headings
Let me know what you think... Bassophile 20:55, 9 February 2006 (UTC)
Hi The Spirit. I'd appreciate any assitance/comments/criticism you have... I think it's a little patchy at the moment. I'm trying NOT to include too much nasty theory, but I suppose some is inevitable. I'm also trying not to duplicate what has already been done elsewhere. There is a nice section on unit cell which includes a good introduction to symmetry etc, which is why I've left that out. I've also not gone into Bragg's and Laue's laws/conditions as they too are covered elsewhere. Let me know what you think so far.
Cheers, Bassophile 15:30, 14 February 2006 (UTC)
A little discussion about your rather major changes to this page would be appreciated! I would argue that the crystallisation and data processing of small molecules and the crystallisation and data processing of macromolecules, whilst being superficially similar, are sufficently different to merit their separate sections, as I had originally laid out. I suggest we combine our efforts and deliniate Small molecule and macromolecular crystallography whilst highlighting the differences and similarities between the two disciplines... Bassophile 20:20, 28 March 2006 (UTC)
I removed the notice about merging this article with crystallography. That article clearly discusses other techniques beside x-ray. It is not clear to me that they need to be merged. Rmhermen 21:01, Nov 14, 2003 (UTC)
Yes, crystallography addresses additional techniques, but those others are also based on diffraction from crystals and on the construction an image by fourier transformation, and so a lot of the explaining that needs doing for one of them needs doing for all of them. I think we should have one good explanation of the commonalities in one article and links to specific articles just for the fine points, such as that a lot of X-ray stuff is going on at synchrotrons and figures in big international proteomics initiatives. 168... 21:51, 14 Nov 2003 (UTC)
The article states that usually one works at 100K. Has it always been this way (and if so, why)? I'm reading an Acta Cryst. of 1976 and it doesn't mention the work temperature. It wold be very interesting to me to know whether I should assume that the determination was done at room temperature or at 100K... Thanks :-)
No, rt was common until cryojets were developed in the 1990's. The use of low temperature significantly improves the data due to less molecular motion and disorder. Hokietiki@hotmail.com 22:38, 29 January 2007 (UTC)
Actually the advantage of 100K is more to do with radiation damage. See, for example, Garman and Schneider 1997. — Preceding unsigned comment added by 129.67.79.78 ( talk) 11:22, 4 May 2013 (UTC)
I updated the link to resolution to Sensor resolution. This might have needed to be a link to Optical resolution. Feel free to change it if you have more insight in to this then me. -- STHayden 22:21, 6 August 2006 (UTC)
I think protein crystallography should have its own page (possibly redirected to from 'macromolecular crystallography') -- different refinement approaches, different ways of phasing, much more trouble with crystal growth ... Fivemack 15:55 21 September 2006
Would anyone like this:
{{User:Bassophile/UBX}}
Bassophile
13:46, 11 January 2007 (UTC)
It's not clear whether the article is about x-ray crystallography (generic field of study and family of analytical techniques) or about the analytical technique of single-crystal x-ray diffraction. It also seems that other methods such as powder diffraction are mixed up in this article. In my line of work few people would refer to powder or thin-film diffraction as "crystallography", whereas the single-crystal jocks call themselves "crystallographers". I have substantial experience in non-single-crystal methods and have started an alternative page x-ray diffraction to clear this up. Irene Ringworm 16:43, 28 February 2007 (UTC)
My understanding is that reliance on fourier transforms in diffraction instrumentation is really as a more modern computational tool. Before advent of computers, who used (or would want to use) fourier transforms to assess a crystal structure? People made Ewald spheres with simple algebra, which was every bit, if not more, "physical," relative to the transform (and contrary to this article, calculations in real space are no less "physical" than those in reciprocal space - its a matter of the more effective tool for the circumstances). It's like saying atomic spectroscopy, born out of diffraction-grating spectroscopy, is based on Fourier transforms, simply because they have, in recent years, found application as very convenient, high-resolution, computational tools.
Because the present-day numerical tools accurately transform the output of the instrument does not make Fourier necessary, let alone central to the historical foundations of the field, or the evolution of its fundamental physics. Wikibearwithme ( talk) 20:52, 18 November 2015 (UTC)
I would call the ribbon structure in the lead image a molecular model rather than an atomic model. Agree? ike9898 21:41, 8 May 2007 (UTC)
The following suggestions were generated by a semi-automatic javascript program, and might not be applicable for the article in question.
between a number and the unit of measurement. For example, instead of 3 mm, use 3 mm, which when you are editing the page, should look like: 3 mm.
[?]You may wish to browse through User:AndyZ/Suggestions for further ideas. Thanks, Wim van Dorst ( Talk) 22:01, 9 May 2007 (UTC)
Can someone provide a reference for "Twinning often occurs when the unit cell has a net electric dipole moment (ferroelectric crystals), because of a subtle interaction between the dipoles of the bulk crystal with polarization charges expressed on the crystal's surface."
Bassophile 07:43, 22 May 2007 (UTC)
Hi all!
The article would benefit from a lot more pictures, don't you think? I'll try to make schematics for the sitting/hanging drop methods and for the kappa goniometer, but my drawing skills are lame and it would be better to have real photographs. A photograph of a precipitate droplet might be nice, too. Images of the electron density at various stages of the phase refinement would also be great, perhaps as a mesh surrounding the final structure as a stick model? Any help would be much appreciated, Willow 14:45, 24 May 2007 (UTC)
This article implies that this technique is solely used for determining the structure of organic molecules and inorganic compounds. However, x-ray crystallography is the science of using x-ray diffraction to understand the structure of crytalline materials, not of molecules per se, and as such includes its use as a tool for geologists looking at the crystal structure of minerals. Is there some reason I am missing that this article has declared the technique to only be a tool in the life sciences? KP Botany 18:44, 27 May 2007 (UTC)
Whether or not I include anything, the article can't be written as if it is something that is not, ie, the entirety of x-ray crystallography, when it is not actually about x-ray crystallography, but only part of it. It's like writing an article about radio waves and labeling it the electromagnetic spectrum. I will tag it for now. KP Botany 17:20, 30 May 2007 (UTC)
Bassophile, while I'm happy you're so knowledgable on the subject that you can write on the fly, I can't. My concern is that readers coming to the article as it now stands will think that x-ray crystallography is a technique for studying organic molecules. It isn't, it is the science of looking at the structure of crystals, some of which are organic, to learn their atomic and/or molecular arrangements. As long as there are sentences like this in the article, "X-ray crystallography is used in chemistry and biochemistry to determine the structures of inorganic compounds, DNA, RNA and proteins," which are clearly false, it has to be tagged to warn readers. Although I've done some x-ray crystallography, it has been quite some time, and I am unwilling to write on the fly about something so complex that I haven't done in a while. When I get my facts straight I will add to this article. You might consider renaming this x-ray crystallography (biological) in the meantime, if you simply don't know anything about the materials aspect, or don't have the inclination to add anything about it. KP Botany 18:15, 31 May 2007 (UTC)
Willow, the real problem now is the article is entirely geared towards biological. I see the introductory paragraph has been changed, but from there it boldly goes on as if the article is all about the biological. I think making it accurate is more important than hurrying up, and, imo, the best Wikipedia editors are those who have lives outside of Wikipedia, so please enjoy your time with family then add material as appropriate. I know people don't like tags like this, but it is important to alert readers that there are issues with article, so they know to be careful about what they take from the article. I think the article should be general about x-ray crystallography, as that is its title, and other articles should deal with the specific techniques. See Electron microscope and Transmission electron microscope and Scanning electron microscope for a good idea of how it can be done. It would be wonderful to get a good series of articles on Wikipedia for the layman on these topics. KP Botany 18:53, 1 June 2007 (UTC)
(reset indent) I've gone over the article again. Please bear with me, if I appear biased. I can only speak for my own experiences. I have absolutely no experience with protein crystallography, and I have no knowledge of the history of crystallography beyond Bragg's law. My experience is as an inorganic chemist - the use of X-ray crystallography to determine the connectivity and the solid state conformations of organometallic compounds.
These are my suggestions.
With regard to #1 and #2, I'll try my best and find some information. Perhaps someone can help with #4. -- Rifleman 82 14:09, 5 June 2007 (UTC)
If there is a lot more information on protein crystallography, perhaps it should be split into a separate article " protein crystallography", which discusses the finer points. The broad strokes can remain here. I.e. diffraction theory, sample prep, data collection and analysis. -- Rifleman 82 14:16, 5 June 2007 (UTC)
130.88.210.108 14:09, 3 July 2007 (UTC)
It still looks very unbalanced as there is a lack of pictures, references and external links for non-biological applications. Even the history section is dominated by biological developments, leaving a couple of short sentences for the early history. GB 03:25, 5 July 2007 (UTC)
"Scientific pre-history of crystals and X-rays" is a bad title for the section. "Pre-history" specifically means before written records, and "Early scientific history" would be more accurate. —Preceding unsigned comment added by 164.67.237.80 ( talk) 02:33, 8 November 2008 (UTC)
Hey there small molecule lovers! I have re jigged the phasing & history section to pay a little more homage to the elucidation of small mols - I even made and dropped in a picture of Penicillin for your enjoyment and delight - I am content and happy to do some more tweakage in most sections, but I am afraid I am not au fait with small molecule crystallisation (drop in it something volatile and leave it to concentrate & crystallise???) or SM data processing, beyond the direct methods stuff. I suggest that someone with SM expertise needs to look at and point out some basic points that need inclusion. However, here are my thoughts:
Willow - FANTASTIC WORK - If I'm stepping on your toes, let me know - I tend to be a little sporadic as my wiki-time can be variable.
Keep up the work, editors! Bassophile 11:02, 13 July 2007 (UTC)
As promised, I've returned to work on the History section and would be grateful for constructive criticism and specific suggestions, especially from editors who still feel that the article is unbalanced. I added a bit of chemistry today and will be adding some physics over the next week or so. It would be helpful to know which results from other fields should be added to our description of X-ray crystallography. Once the content is more-or-less agreed upon, we can add all the inline citations and figures. Thanks for your help! :) Willow 21:44, 30 August 2007 (UTC)
I'd like to come up with a list of Figures that might augment the article. Here are some of my initial thoughts; please give me your ideas on these, and feel free to add more!
I realize this article is getting long and detailed. However, I'd like to get a complete picture of the field before we fork off daughter articles. Thanks for your patience! :) Willow 16:55, 31 August 2007 (UTC)
Keep up the good work Willow! From the text books I have including the topic:
Graeme Bartlett 22:49, 31 August 2007 (UTC)
I'm not sure if the template is still necessary, but in any case it was misleading IMO. The template said "This article's representation of one or more viewpoints about a controversial issue may be unbalanced or inaccurate." IMO this is not a controversial issue, but only a matter of missing information and balance. I've replaced it for now with the {{ missing information}} template, which I hope will be more accurate and explicit. It says "Concern has been expressed that this article or section is missing information about: minerals and crystals that are not molecular/biological." -- Itub 09:01, 18 September 2007 (UTC)
I've noticed that the article is getting a bit long. The lead is longer than the recommended limit of four paragraphs (it currently has five slightly long paragraphs), and some parts of the article could probably be split out and summarized. I think the easiest one to split out would be the history. -- Itub 16:07, 21 September 2007 (UTC)
The introductory section of this article is incorrect. X-ray crystallography isn't about the "beam of X-rays being deflected by the crystal." That's what all this nonsense about lattice planes, unit cells, diffraction patterns and the like is about--x-ray crystallography uses the atomic arrangement of a crystal, not the macrostructure. KP Botany 22:42, 22 September 2007 (UTC)
Wikipedia:Talk page:"Article talk pages are provided for discussion of the content of articles and the views of reliable published sources. They should not be used by editors as platforms for their personal views." Nor for your personal opinions about me--these can go on user talk pages if they are related to a Wikipedia issue, otherwise they don't belong here period. It's always nice to see editors working so hard on an article that they have the time to use an anony IP to get in a personal attack. I suggest spending the time reading up on x-ray diffraction, instead. KP Botany 17:49, 23 September 2007 (UTC)
Wow. KP Botany 17:49, 23 September 2007 (UTC)
The talk page stands as it was when I put the disputed tag back. You have not dealt with the issue that caused the tag to be placed there. Please do so by putting a general introduction into what x-ray crystallography does and how it does it into the article before removing the tag again. KP Botany 02:04, 24 September 2007 (UTC)
It's not semantic hair splitting when the fact is crystallography is based upon the relationship between the atomic spacing and the wavelength of x-radiation. And it's bothersome to me that the editors of this article can't seem to grasp or deliver this idea to the audience. A mirror delivers a reflection that can be seen with visible light, understanding a mirror image can be accomplished through simple optical theory without ever getting to the atomic level. X-ray crystallography's foundation depended upon understand the relationship between the lattice structure of a crystal and the wavelength of x-rays. This is NOT semantic hair splitting, this is the underlying theory that directly led to the field. KP Botany 01:32, 27 September 2007 (UTC)
The present article, though we are calling it X-ray crystallography, is basically talking about single-crystal X-ray crystallography of biological molecules. I think it should not be too much trouble to fix up the naming later, and it may not be necessary to adjust the scope. If powder diffraction is considered an important topic, I think it can be handled in a separate article. There should not be too much duplication.
I spent some time looking over one of the cited references today, Glusker, Lewis and Rossi (1994), Crystal Structure Analysis for Chemists and Biologists. Their main distinction was between small molecules and large molecules. They give only a small amount of coverage to powder diffraction. They do NOT make a big distinction between diffraction studies of inorganic and organic molecules, so far as I can tell. Crystals are crystals. Their main focus (in an 854-page book) is not telling people how to do the studies, but how to interpret the results. They have a lot of chapters on applications, i.e., on what has been learned about specific structural problems by X-ray diffraction. They include some inorganic stuff in their application chapters. The point of my comment here is to show that adjusting this article to be sure it addresses small molecules and inorganic problems is probably not a large change. Also, the more recent books on crystallography that I found on the library shelf tend to use 'X-ray crystallography' as a term to cover MOSTLY single-crystal (non-powder) studies and MOSTLY larger molecules. So I don't believe our choice of names is wildly off. EdJohnston 22:14, 24 September 2007 (UTC)
One of the 'to-do' items listed above is 'Better treatment of the historical development.' For your consideration I offer the list of Nobel winners who made use of X-ray diffraction, or advanced the method. This could be made into a table like the one in Nobel Prize in Chemistry but it could be expanded to list one of the molecules that each one studied and its molecular weight. This would probably become a separate article if other people think it is a good idea. Here are the Nobel winners I identified.
NOBELISTS who worked on X-ray diffraction of solids:
Let me know if you think this is a good idea. We could try to fit the material into the present article but it's already quite large. Most likely it should be a separate article. EdJohnston 23:03, 24 September 2007 (UTC)
See the comment above by User:Irene Ringworm:
It also seems that other methods such as powder diffraction are mixed up in this article. In my line of work few people would refer to powder or thin-film diffraction as "crystallography", whereas the single-crystal jocks call themselves "crystallographers".
My own web searches gave results consistent with her comment. This suggests we might replace the following sentence:
WITH
Comments? EdJohnston 02:41, 25 September 2007 (UTC)
Willow expanded the caption for Image:Eden.png in the section X-ray crystallography#Model building and phase refinement.
An example of electron density for a protein crystal structure at 2.7 Å resolution. The heavy atoms of an arginine residue (upper left), a tyrosine residue (lower left) and a disulfide bond (upper right, in yellow) are highlighted. The intervening bonds represent the heavy atoms of peptide groups, while the smooth green tube running throughout represents a spline fit to the polypeptide backbone.
It's fine to provide more detail, but I'd lose the 'heavy atom', which suggests metals. Also if we are going to point everything out, perhaps numbers should be added to the diagram.
For comparison here's the original caption supplied by Bassophile when he made the diagram:
An example of electron density contoured at 1 sigma, of a crystal structure solved to 2.7 Å resolution. An Arginine residue (top left), a tyrosine residue (bottom left) and a disulphide bond (right) are highlighted
The version just preceding Willow's was the same as Bassophile's but with the 'top left' etc. parenthesized directions left out, which I agree are helpful for understanding. I tinkered a bit with new versions of the caption, but I think it's too hard for people to precisely figure out that picture. (There seem to be too many green tubes). Bassophile's caption (with the 'top left' etc included) I think is preferable. Note also there is a slight licensing problem with the image, in that Bassophile wanted to restrict use of the picture to just this article, which I think muddies the GFDL: Permission granted in Xray_Crystallography page - for other uses contact Author. EdJohnston 17:28, 26 September 2007 (UTC)
90.204.105.203 20:28, 11 October 2007 (UTC) That was me, btw Bassophile 20:31, 11 October 2007 (UTC)
It'd be helpful to have a clear roadmap to remove the "disputed facts" tag. I'm personally unaware of any incorrect statements in the present article, but I'm perfectly willing to believe that there might be some. It'd be nice to have them listed specifically, all in one place, here in this section, so that we can deal with them one-by-one and strike them from the list, similar to what's done at FAC. Once the disputed facts have been resolved, we can remove the tag. Willow 23:00, 28 September 2007 (UTC)
Likewise, it'd be helpful to list specific items of "missing information" that should be added to the article, so that we can add them and remove that tag as well. The spirits are willing, but the direction is weak — or at least Delphic. ;) Willow 23:00, 28 September 2007 (UTC)
I put these tags here for deficiencies in the article that have yet to be addressed. Namely, the article lacks an outline, a coherent understanable general explantion of the topic and development of the various uses of x-ray crystallography in a logical fashion, such as single crystals, chemistry, proteins, DNA. Don't start an edit war, and don't delete the tags just because chemistry is your area and it covers chemistry. X-ray crystallograpy is used extensively in the materials science industry for quality control, and has been used for this purpose for decades. To ignore it because you're a chemist is fine in your profession, but it's not fine for a Wikipedia article. KP Botany 01:51, 8 October 2007 (UTC)
Geeze, now I'm supposed to believe that hexamethylenetetramine is a rock or what? What is it with you and this article that you don't see how crappy it is, how disorganized it is, and how much it is missing? People will come here and think just like the lot of you that x-ray crystallography is something used by chemists and biologists exclusively. The article is a piece of crap. Good grief, one ionic crystal is used to describe the use of x-ray crystallography in all of materials science and geology?
Fine, the article is a piece of shit. Put all of you want it this way, and clearly our latest editor owns it enough to declare that a single inganic crystal makes the article perfect.
Keep the crap. KP Botany 14:04, 8 October 2007 (UTC)
This article should be moved to X-ray crystallography (organic) so everyone who thinks that the science is solely used by chemists to study organic molecules and by biologists can have the article that all of you so obviously want. Then it's fine by me to remove the tags. But without the tags, that you are removing without cleaning up this piece of shit, this article needs gone from its current title. Because you're lying to the readers--it's not about X-ray crystallography, it's about organic molecule x-ray crystallography. KP Botany 14:06, 8 October 2007 (UTC)
I will not edit a single piece of this article because editors do not want it to be anything other than an article on the x-ray crystallography of organic substances. That is not what x-ray crystallography is, a field limited to organic substances. It is a vast field that includes applications in metallurgy, materials science, crystallography, mineral identification, volcanology and other areas. The editors of this article have focused on minor points in the field without a clear outline of its historic development and the applications. The editor removing the tags is doing so without any knowledge of what is missing, or any concern for the quality of article that editors present to readers. As such is the case, I simply must concede ownership to him/her and his superior knowledge of wikilawyering to get the tags removed from this article at all costs. KP Botany 14:10, 8 October 2007 (UTC)
“ | The structure of diamond was solved in the same year, proving the tetrahedral arrangement of its chemical bonds and showing that the C-C single bond was 1.52 Ångströms. Other early structures included copper, calcium fluoride (CaF2, also known as fluorite), calcite (CaCO3) and pyrite (FeS2) in 1914; spinel (MgAl2O4) in 1915; the rutile and anatase forms of titanium dioxide (TiO2) in 1916; pyrochroite and, by extension, brucite [Mn(OH)2 and Mg(OH)2, respectively] in 1919; and wurtzite (hexagonal ZnS) in 1920. | ” |
Wow, I take a little vacation to work on Catullus, and everything goes crazy! Let's all take a little nap, shall we, and then return in a few hours to reach consensus?
I hope that we agree that this article is not a battle-field, nor a place to posture and needle one other; anyone wanting to do that is encouraged to find another outlet. We're all here to improve the article, right? And we can't do that unless we can articulate what's wrong with it; we need to diagnose its failings and find a cure. All we're asking for is a clearly defined set of criticisms that we can address.
Personally, I think the article is OK as is, and probably deserves its "B" ranking. It could be a lot better, though; I totally admit that. It suffers from weak flow in its writing and haphazard treatment of sundry topics. I wrote it pretty much single-handedly as part of the May Science Collaboration of the Month (that wasn't), and single-author works are notoriously stilted, especially when the author is no expert. The parts left over from before May are also pretty bad. Nevertheless, I've worked hard to improve the article, and it serves no good purpose to simply dismiss it as excrement. We would all do better if you could just find your voice and articulate exactly what facts are incorrect, what exactly you'd like to have added, how you'd improve the article, and what changes in its organization you'd recommend. Your previous comments, while clearly negative, have been pretty vague; at least they seem so to me. How can we fix the article if you won't tell us what's wrong? I know you can do better; please rise to the occasion now or tell us when you will be able to. Willow 16:00, 8 October 2007 (UTC)
"There has been some discussion of this in the past. Most small molecule crystallography seems to have be placed in powder diffraction (yes, I am aware there is a difference!). If you wish to add a section pointing out the differences between small molecule and macromolecular crystallography, such as more emphasis on direct methods, different crystallisation methods etc... go for it (be bold)! Bassophile 14:55, 30 May 2007 (UTC)" Bassophile 20:45, 11 October 2007 (UTC)
A 10 MB animated .gif, that is not even closely related to X-ray crystallography, takes ages to load and doesn't illustrate the concept much better than an ordinary image with labelled angles. However, I feel the image might be useful in an article on goniometers; it just shouldn't load on default. —Preceding unsigned comment added by 84.161.129.78 ( talk) 18:27, 1 March 2008 (UTC)
I'm just wondering if anyone would help spruce up the article on Laue equations? Thanks. Veritas ( talk) 01:12, 12 March 2008 (UTC)
Can anyone throw any light on this phrase please: "the John Wayne of crystallography" was the description given by Luzzati* of David Harker, the American X-ray crystallographer?
thanks,
nitramrekcap 17:16, 11 April 2008 (UTC) Talk:X-ray crystallography/Archive 1/GA1
"Walter Friedrich and his assistant Paul Knipping, to shine a beam of X-rays through a sphalerite crystal" is wrong. The crystal used was Copper(II) sulfate. This can be verified from the Max von Laue Nobel lecture. Avihu ( talk) 20:09, 17 February 2009 (UTC)
the title basically explains the question — Preceding unsigned comment added by Ammaralsheik ( talk • contribs) 17:09, 12 July 2011 (UTC)
Would anyone find it useful to include, near the 'Further Reading' or 'External Links' subsections, a new, compact subsection that lists the main scientific conferences in the field of X-ray crystallography (and links to the respective pages on wikipedia, such as Mid-Atlantic Crystallography Meeting ? Cmura ( talk) 02:01, 30 November 2010 (UTC)cmura
Portal:Xray Crystallography, a portal related to this topic, has been nominated for deletion. Your opinions on the matter are welcome; please participate in the discussion by adding your comments at Wikipedia:Miscellany for deletion/Portal:Xray Crystallography and please be sure to sign your comments with four tildes (~~~~). You are free to edit the content of Portal:Xray Crystallography during the discussion but should not remove the miscellany for deletion template from the top of the page; such a removal will not end the deletion discussion. Thank you. ··· 日本穣 ? · 投稿 · Talk to Nihonjoe · Join WP Japan! 17:11, 15 September 2012 (UTC)
Subject appears to lack sufficient notability for a stand alone article. Suggest folding it in with X-ray crystallography. Ad Orientem ( talk) 01:14, 30 January 2014 (UTC)
Can anyone tell me about the techniques of X-ray crystallography and how this technique can be used to determine the crystalline structure of solid substances such as sodium chloride. — Preceding unsigned comment added by 2.91.106.63 ( talk) 10:06, 14 September 2019 (UTC)
It is very odd to have this much focus on an institution in an article about a workhorse scientific method. Without disparaging Dundee, it isn't even the place where this X-Ray crystallography was invented. Maneesh ( talk) 02:57, 12 March 2021 (UTC)
103 link is dead
The lead section of this article is too long (as perhaps is the entire article). WP:Lead would have even an article this long only have a three to four paragraph lead while there are five paragraphs here. Too much is repeated from the lead in the definition section as well. Rmhermen 15:48, 24 September 2007 (UTC)
What are omit maps? I read a sentence about them in the article, but it's not explained, so I tagged it clarification needed. Please clarify, and thanks. Crystal whacker ( talk) 23:15, 5 October 2008 (UTC)
This article appears to be misleading because it ignores the work of Karle and Hauptman who won the 1985 Nobel prize for chemistry for their much earlier work on the recovery of crystal structures from x-ray diffraction data. —Preceding unsigned comment added by Jfgrcar ( talk • contribs) 04:19, 27 November 2010 (UTC)
The sentence: "The intensity of Thomson scattering declines as 1/m2 with the mass m of the charged particle that is scattering the radiation; hence, the atomic nuclei, which are thousands of times heavier than an electron, contribute negligibly to the scattered X-rays." is very not-intuitive even though it is presented as a matter of fact. It would be good to add something like "this means that large atoms scatters more intense than smaller ones". Also, the "intensity of scattering" is quite hard to comprehend anyway - does it mean that the waves scatter in a broader angle or that certain angles have a higher intensity of the out-coming waves?
Just above that sentence, the words "valence electron" and "free electron" are used - it would be nice, if it was explained, why there should be a difference in the interaction between the X-ray and those two different types of electrons in the material. OxygenBlue ( talk) 10:15, 14 January 2013 (UTC)