Talk:Crystal system

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[edit] Overhaul needed

This article is rather chaotic and contains a lot of information that in my opinion belongs elsewhere. This article should in my opinion concentrate on describing the 7 crystal systems (cubic, tetragonal etc) and explaining the restrictions on the axial system (cubic: a=b=c, α=β=γ=90°, etc). A short explanation on the relationship with Bravais lattice should be given, but there should be a separate article for that subject (the two should not be merged as they are now). Info on crystallographic point groups should be covered in that article, and not here. This will result in a much shorter article, so I want to hear any comments first. If there are none, I'll implement the changes within a couple of days. O. Prytz 18:44, 8 January 2006 (UTC)

Some time ago I have combined several pages into Crystal system, because of the strong relationships, and the convenience of having all this related information in one place. In the two tables the first column is crystal system: these tables provide details about each crystal system (overview of all point groups possible for the crystal system, etc.), so they are not at all off-topic.--Patrick 03:07, 9 January 2006 (UTC)

I see. I'm not sure what the Wikipedia policy on merging is, but it seems to me that articles should not be merged just because they are related. Some mention of the relationship is of course good, but I still believe there should be separate articles, with this one being quite a bit shorter and more to the point. To be specific: the first table (of point groups by crystal system) would be better off in the crystallographic point group. The second table could perhaps be kept here, but the relationship between crystal system and Bravais lattice should be spelled out more clearly. This would, perhaps, cause a significant overlap with a future article on Bravais lattice, but I think it would be good for clarity. O. Prytz 08:12, 9 January 2006 (UTC)

Earlier I made crystallographic point group a redirect, because with Crystal system and Point groups in three dimensions it seems superfluous. That was reverted, and now we have the odd situation that other pages provide better info about crystallographic point groups than that page itself. If that page is kept we can perhaps best put the first table in a template, and call it from there also. For people familiar with point groups the table provides info about the crystal systems, so I like to keep it here also.--Patrick 11:20, 9 January 2006 (UTC)

I agree that crystallographic point group may be somewhat lacking, but I don't agree that for example Point groups in three dimensions gives 'better info'. I understand that you have contributed heavily to that article, and I don't want to offend you, but I'm afraid that article is almost unreadable to anyone who doesn't already know the topic.

My concern is the following: I believe the average reader of the 'point group', 'space group', 'crystal system', 'crystal class' etc articles will (at best) be undergraduates in physics or chemistry or perhaps graduates without previous experience with the subject. I'm sorry to say that any such people getting started in solid state physics/chemistry or crystallography, and wondering what the heck a point group is, won't get any help from the Point groups in three dimensions article. Sorry. For them, the crystallographic point group article would be a better starting point, although it is a bit short.

On the other hand: I think what we've now done with screw axis and glide plane is pretty good. They have a short intro (which perhaps should be expanded) giving the general idea, and then a more formal treatment in a seperate part. The same is the case for space group, although here I'm a bit worried now about the length of the group theory part.

At some point I'll start doing edits here, so we'll have to take disagreements as they come along. O. Prytz 19:31, 9 January 2006 (UTC)

I've started editing the Bravais lattice article. O. Prytz 22:18, 9 January 2006 (UTC)

[edit] Overhaul needed

I agree. There are a lot of related pages, and they are somewhat chaotic too. We should try to consolidate all the different pieces of information into a set of concise pages. Also we need to implement the different focus of crystallographers, protein crystallographers and mathematicians. This is why I added the 'enantiomorphic' column to the table of point groups, as protein crystallographers are not interested in centrosymmetric point groups. --Dan|^(talk) 09:59, 31 January 2006 (UTC)

For example, we don't appear to have consistent names for the seven crystal systems. The two different tables in this article use different names. --Dan|^(talk) 10:43, 31 January 2006 (UTC)

Yes, the whole area of crystallography is in shambles... although I think space group is ok now. Would you be interested in starting work on for example point group or crystallographic point group along with me ane any others who are interested? Lots of other articles need work as well... O. Prytz 16:06, 6 February 2006 (UTC)

I just wish I had the time! I am hapy to add things here and there as I can, but we prolly need a 'plan of action' so we can all work to the same tune... --Dan|^(talk) 23:25, 22 February 2006 (UTC)