Talk:Crystal structure

message: The text, as it is, implies Miller Indices are only applicable to cubic systems. As far as I know this is incorrect- they are applied to non mutually orthogonal axes as well.
:Changed. Thank you. Materialscientist (talk) 00:30, 1 March 2010 (UTC)
thread_title:  Miller Indices

message: There doesn't appear to be anywhere on Wikipedia where primitive lattice vectors for various lattices are explicitly stated. E.g for FCC,BCC etc. I think it would be useful for any student looking for such information.
I added the FCC vectors to the diamond page but they were removed! I could add a list in a new section on this page if thought appropriate.  
Thanks Lukehounsome
:There is something like this on Cubic (crystal system), you could add info there and on similar pages.--Patrick 12:43, 8 February 2006 (UTC)
thread_title:  Lattice vectors 

message: Has anyone taken on the task of making them SVG images? This would be nescessary in any case if the periodic table of Wikipedia:WikiProject_Elements would be converted to SVG. --Dschwen 22:18, 2 March 2006 (UTC)
replies: text: I've made a .svg of the hexagonal lattice. Image was based on Cubic structures by User:Baszoetekouw - Danieljamesscott 13:23, 23 October 2006 (UTC)
thread_title:  Crystal illustrations 

message: I'm making some changes to this article. We already have articles for crystal system, Bravais lattice, crystallographic point group and space group. Some of these articles are ok, but we need to tie all of these concepts together, and I believe this article is the right place to do that. So I'm trying to structure this article so that it will give a good overview of the different concepts, while still being short and concise. I'd be happy to have som help in this though. O. Prytz 22:05, 7 June 2006 (UTC)
thread_title:  Making some changes 

message: Introduced concept of 'motif' and distinguished it from 'unit cell' (which is strictly a geometric construct).  
Dr Thermo 19:13, 19 July 2007 (UTC)
thread_title: Motif/Unit Cell

message: The rhomohedral unit cell should show that the three angles are equal.
Dr Thermo 19:14, 19 July 2007 (UTC)
thread_title: Rhombohedral

message: Introduced improper rotatation and distinguished between symmety operations and symmetry elements.
Dr Thermo 19:46, 19 July 2007 (UTC)
thread_title: Point and Space Groups

message: The two images of monoclinic structure in the table aren't displayed.  Instead there are text links to the correct image pages.  Any idea what's going on?  I'm using Firefox 2.0.0.6.  I have no experience dealing with images on Wikipedia; sorry! Matt 17:01, 18 September 2007 (UTC)
thread_title:  Monoclinic pictures not displaying 

message: While I admire the physicists, geologists, and chemists on this page, in the biology and structural biology fields, a crystal structure is uniformily known as the biomolecular product of X-Ray Crystallography.  I suggest a link at the top to disambiguate this. Amboo85 (talk) 01:49, 20 December 2007 (UTC)
thread_title: Biological Relevancy

message: Unit cell redirects here, but that concept is broader than strictly crystal structure. For example, foams can be characterized by their unit cells (e.g. to distinguish closed-cell and open-cell foam). --Delirium (talk) 03:05, 13 April 2008 (UTC)
thread_title:  unit cell in other materials 

message: I changed a sentence early on in the Polymorphism section that read:
"According to Gibbs' rules of phase equilibria, these unique crystalline phases will be dependent on such intensive variables as pressure, temperature, and volume."
to read:
"According to Gibbs' rules of phase equilibria, these unique crystalline phases will be dependent on intensive variables such as pressure and temperature."
Volume is not an intensive variable; it is extensive, as it is dependent on the size of the system.
Jthechemist (talk) 16:14, 29 July 2010 (UTC)
thread_title: Correction of reference to volume as an intensive variable

message: This section, as of 8 April 2011, seems too long and too complicated for this article. It is largely historical information, with a narrow focus on transition metal salts, metals and intermetallics. If this stuff is still state-of-the-art CSP in 2011, we should find a recent review to prove the original 1930s-1950s papers are worth including.
Phys. Chem. Chem. Phys. (2010) 12 (30) was a special issue on "solid state and cluster structure prediction". There should be plenty of up-to-date summaries of the field present in those articles.
I propose Crystal structure#Prediction of structure be shortened and most of the content moved to Crystal structure prediction. A sentence or two should be written about molecular CSP, as it's just as important as predicting the structure of metals and other simple inorganic network structures. Predicting and understanding polymorphism, particularly in pharmaceuticals, is a very important application of molecular CSP. I suspect its importance dwarves that of the stuff mentioned here at the moment.
Ben (talk) 09:42, 8 April 2011 (UTC)
thread_title:  "Prediction of structure" section 

message: In the polymorphs section, someone edited my previous change (noted above) to state that both pressure and temperature are extensive variables. They are actually intensive, as they are independent of the scale of the system.
Proof: from the ideal gas law we know that PV = nRT. The # of moles (n) is extensive (scales with amount of material), and so is the volume (V). If we scale the entire system by a factor of two, the # of moles doubles and so must the volume. The pressure (P) and temperature (T) will remain constant, and are therefore intensive properties. I think this point gets lost on many physical chemistry students.
See intensive and extensive properties for the correct definition. Both pressure and temperature are correctly classified as intensive there.
Original sentence:
"According to Gibbs' rules of phase equilibria, these unique crystalline phases will be dependent on extensive variables such as pressure and temperature."
New sentence:
"According to Gibbs' rules of phase equilibria, these unique crystalline phases will be dependent on intensive variables such as pressure and temperature."
Jthechemist (talk) 23:57, 20 August 2011 (UTC)
thread_title:  Intensive vs. extensive variables wrong again 

message: Principal axis (crystallography) redirects here, but isn't defined in the article. Ratzd'mishukribo (talk) 18:57, 30 March 2012 (UTC)
replies: text: I now redirected Principal axis (crystallography) to the appropriate subsection. Ratzd'mishukribo (talk) 20:23, 10 September 2012 (UTC)
thread_title:  Principal axis 

message: I think that this article should also discuss the asymmetric unit so that we can make Asymmetric unit redirect here. Bmdubs (talk) 06:13, 9 July 2012 (UTC)
thread_title:  Asymmetric unit 

message: The two terms are closely related and the subject matter and content are overlapping and redundant. This article is now much better, but ideally I would prefer to have the information under "Crystallography" particularly as 2014 is going to be the International Year of Crystallography (http://www.iycr2014.org/).  A redirect would be OK, but I feel it would be best if people see a good Wikipedia article with that term, as this now is. Martino3 (talk) 18:01, 30 December 2013 (UTC)
thread_title:  Merger with [[Crystallography]]? 

message: The definiton of angles of the monoclinic system seem to be different from other sources.
--Uvainio (talk) 12:32, 5 May 2016 (UTC)
thread_title: Monoclinic

message: See my more-detailed list of suggestions at Talk:Crystallography#Article badly needs improvement.
Related suggestions for the Crystal structure article here:
#Import/merge Crystallography#Notation to here, or just delete it as redundant.
#I am not recommending a merge of the two articles. The one here covers a key but specialized technical treatment of crystal groups, while the Crystallography article should give an overview of the science and field of study as a whole.
#As detailed in Talk:Crystallography#Article badly needs improvement, an infobar template might be very useful for navigating the cluster of articles related to crystallography. If nobody suggests a better alternative, I may start setting up such a navbar myself. For an example of what might be possible, see Template:HVAC, which I created and largely populated, to help organize the chaotic cluster of Wikipedia articles related to that field. Or look at Template:Geology, for an example covering a field of science and related studies.
Reify-tech (talk) 18:06, 12 April 2019 (UTC)
thread_title: [[Crystallography]] article needs help