On Thursday, June 14, 2012 12:06:13 pm James Stroud wrote:
> Hello All,
>
> I would like to discuss symmetry axes, but I'm not sure what the notation
> convention is. For example, I'd like to say something about a 2(1) along the
> x-axis, but the phrase "the 2(1) symmetry axis along x" is a bit cumbersome
> to repeat many times or to put in a table. So I'd like a shorthand, maybe
> something like "x(2_1)" (where the preceding "_" means that the "1" is
> subscript. Another way I like is "x_{2(1)}" (where the curly braces mean that
> all of "2(1)" is subscript).
>
> Does anyone know what the convention is or if there is one?
One would think that this document would have the answer:
http://www.iucr.org/resources/commissions/crystallographic-nomenclature/symel
But it's too cryptic for me.
I'd go with the full expression in the text.
For table entries, I'd want something shorter.
International Tables for Crystallography, Vol A defines the glyph used to
indicate
2_1 screws in the space group diagrams (a solid oval with two flagella).
But finding a font to print it in your table could be challenging.
There is a cryst.mf font for TeX if that helps.
<http://www.tex.ac.uk/CTAN/fonts/cryst/>
I can't find these symbols in the Unicode character tables.
Perhaps the IUCr should propose to have Unicode code points assigned for
the standard set of crystallographic symmetry elements.
Ethan
--
Ethan A Merritt
Biomolecular Structure Center, K-428 Health Sciences Bldg
University of Washington, Seattle 98195-7742
