[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re:[sdpd] Miller index in R-3c space group
The conditions limiting the possible reflections for the space group R-3c are, for the class h0l,
2h+l=6n so the reflection 303 is clearly forbidden, in that space group.
The rule -h+k+l=3n is common to both the space groups as general condition but the c glide plane in the space group 167 introduces other special conditions for the h0l, h-hl and 0kl reflections.
Regards
Ferdinando
---------- Initial Header -----------
>From : "Marco Sommariva" marco.sommariva...@mater.unimib.it
To : "Newsletter SDPD" sdpd...@yahoogroups.com
Cc :
Date : Wed, 2 Feb 2005 18:24:27 +0100
Subject : [sdpd] Miller index in R-3c space group
>
> Good evening,
> I have a question about Miller indexes (h k l) in the space group R-3c (n° 167):
> in the article Chem. Mater. 2003, 15, 2084-2093 the authors writes:
> <<The XRD patterns clearly show reflections such as (3 0 3) which is normally forbidden in the R-3c space group... the space group is unambiguously R-3 rather than R-3c..>>.
>
> I can't understand why (3 0 3) is forbidden in R-3c, since the general reflection condition is: -h+k+l=3n.
> But this rule is present also in the space group R-3 (n°148) !
> And what does it means <<normally forbidden >> ?
> Does 'n' must be always different from zero?
> Thanks a lot for explanations,
> marco
>
>
>
>
> Marco Sommariva
> Department of Materials Science
> University of Milano - Bicocca
> Via R. Cozzi 53 - 20125 MILAN, ITALY
> Phone +39.02.6448.5141 (5142)
> Fax +39.02.6448.5400
> e-mail: marco.sommariva...@mater.unimib.it
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
____________________________________________________________
6X velocizzare la tua navigazione a 56k? 6X Web Accelerator di Libero!
Scaricalo su INTERNET GRATIS 6X http://www.libero.it
------------------------ Yahoo! Groups Sponsor --------------------~-->
Has someone you know been affected by illness or disease?
Network for Good is THE place to support health awareness efforts!
http://us.click.yahoo.com/RzSHvD/UOnJAA/79vVAA/UIYolB/TM
--------------------------------------------------------------------~->
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/sdpd/
<*> To unsubscribe from this group, send an email to:
sdpd-unsubscribe...@yahoogroups.com
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/