This does seem confusing! Maybe the International tables have changed, but in my copy spacegroup 143 is labelled P3
Spacegroup 146 is equivalent to P3 with translations 1/3,2/3.2/3 and 2/3,1/3,1/3 is called rhombehedral This can be indexed with. "a=b=c in the rhombehedral setting" and labelled R3, but it is usually and more conveniently indexed in " the hexagonal setting with a=b, and gamma = 120", and with the translations to alternate origins 1/3,2/3.2/3 and 2/3,1/3,1/3 labeled R 3:H See this extract from $CLIBD/syminfo.lib begin_spacegroup number 146 basisop x,y,z symbol ccp4 146 symbol Hall ' R 3' symbol xHM 'R 3 :H' symbol old 'H 3' symbol laue '-P 3' '-3' symbol patt '-R 3' '-3' symbol pgrp ' P 3' '3' hklasu ccp4 '(h>=0 and k>0) or (h=0 and k=0 and l>=0)' mapasu ccp4 0<=x<=2/3; 0<=y<=2/3; 0<=z<1/3 mapasu zero 0<=x<=1/3; 0<=y<=1/3; 0<=z<1 mapasu nonz 0<=x<=1/3; 0<=y<=1/3; 0<=z<1 cheshire 0<=x<=2/3; 0<=y<=2/3; 0<=z<=0 symop x,y,z symop -y,x-y,z symop -x+y,-x,z cenop x,y,z cenop x+2/3,y+1/3,z+1/3 cenop x+1/3,y+2/3,z+2/3 end_spacegroup On Wed, 22 Jul 2020 at 12:32, David Vizarraga Revuelto <dvr...@ibmb.csic.es> wrote: > Dear all, > > Let me ask a question about the P3,H3, R3 space group annotations. > I had the idea that H3 was the recommended annotation for the hexagonal > representation of R3 (space group number 146). However, in the Birbeck > space groups web page (attached) H3 is associated with the space group > number 143 corresponding to P3. Similarly for all the other H groups > assigned in the page. Moreover in the web page none of the R space groups > is assigned to an H annotation. > > H3 corresponds to 143 or to 146? > Is there a space group 154 annotated as H32 1 2? > > Many thanks. > > > > "Note that the figure showing the relationship between primitive and > R-centred rhomohedral cells with hexagonal axes is clickable > > Rhombohedral with Hexagonal axes > 146. *R* 3 <http://img.chem.ucl.ac.uk/sgp/large/146bz1.htm> 148. *R* -3 > <http://img.chem.ucl.ac.uk/sgp/large/148bz1.htm> 155. *R* 3 2 > <http://img.chem.ucl.ac.uk/sgp/large/155bz1.htm> 160. *R* 3 *m* > <http://img.chem.ucl.ac.uk/sgp/large/160bz1.htm> 161. *R* 3 *c* > <http://img.chem.ucl.ac.uk/sgp/large/161bz1.htm> 166. *R* -3 *m* > <http://img.chem.ucl.ac.uk/sgp/large/166bz1.htm> > 167. *R* -3 *c* <http://img.chem.ucl.ac.uk/sgp/large/167bz1.htm> > H-centred Trigonal > 143. *H* 3 <http://img.chem.ucl.ac.uk/sgp/large/143bz1.htm> 144. *H* 31 > <http://img.chem.ucl.ac.uk/sgp/large/144bz1.htm> 145. *H* 32 > <http://img.chem.ucl.ac.uk/sgp/large/145bz1.htm> 147. *H* -3 > <http://img.chem.ucl.ac.uk/sgp/large/147bz1.htm> 149. *H* 3 2 1 > <http://img.chem.ucl.ac.uk/sgp/large/149bz1.htm> 150. *H* 3 1 2 > <http://img.chem.ucl.ac.uk/sgp/large/150bz1.htm> > 151. *H* 31 2 1 <http://img.chem.ucl.ac.uk/sgp/large/151bz1.htm> 152. *H* > 31 1 2 <http://img.chem.ucl.ac.uk/sgp/large/152bz1.htm> 153. *H* 32 2 1 > <http://img.chem.ucl.ac.uk/sgp/large/153bz1.htm> 154. *H* 32 1 2 > <http://img.chem.ucl.ac.uk/sgp/large/154bz1.htm> 156. *H* 3 1 *m* > <http://img.chem.ucl.ac.uk/sgp/large/156bz1.htm> 157. *H* 3 *m* 1 > <http://img.chem.ucl.ac.uk/sgp/large/157bz1.htm> > 158. *H* 3 1 *c* <http://img.chem.ucl.ac.uk/sgp/large/158bz1.htm> 159. *H* > 3 *c* 1 <http://img.chem.ucl.ac.uk/sgp/large/159bz1.htm> 162. *H* -3 *m* > 1 <http://img.chem.ucl.ac.uk/sgp/large/162bz1.htm> 163. *H* -3 *c* 1 > <http://img.chem.ucl.ac.uk/sgp/large/163cz1.htm> 164. *H* -3 1 *m* > <http://img.chem.ucl.ac.uk/sgp/large/164bz1.htm> 165. *H* -3 1 *c* > <http://img.chem.ucl.ac.uk/sgp/large/165cz1.htm> > > ------------------------------ > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
