It well-known in the mathematics community to refer to these as Sohnke groups, or even Jordan-Sohnke groups. Camille Jordan identified them in 1868-1869, and L. A. Sohnke in 1879. William Barlow derived all 230 space groups by adding reflection operations to Sohnke's 65 groups in 1894-1989.
On May 2, 2014, at 11:42 AM, Jrh Gmail wrote: > Dear George > My student class would not find that IUCr dictionary definition helpful. What > they do find helpful is to state that they cannot contain an inversion or a > mirror. > To honour Sohnke is one thing but is it really necessary as a label? You're > from Huddersfield I am from Wakefield ie let's call a spade a spade (not a > 'Black and Decker'). > Cheers > John > > Prof John R Helliwell DSc > > On 2 May 2014, at 17:01, George Sheldrick <gshe...@shelx.uni-ac.gwdg.de> > wrote: > >> In my program documentation I usually call these 65 the Sohnke space groups, >> as defined by the IUCr: >> http://reference.iucr.org/dictionary/Sohnke_groups >> >> George >>
