Hello Everyone and especially symmetry experts, I found at http://img.chem.ucl.ac.uk/sgp/medium/003dy1.htm that B2 (SG #2) is a recognized space group that has a basis rotated from P2 (and as a result has two new positions).
I'm wondering whether a similar B2 for P2 (LG #3) is recognized for the layer groups? I checked wikipedia (http://en.wikipedia.org/wiki/Layer_group) and the Bilbao server (http://www.cryst.ehu.es/subperiodic/get_sub_gen.html) and could find no evidence of a B2 layer group being recognized, but I can also come up with no logical reason why it shouldn't be recognized. Thank you for any input, James -- James Stroud http://www.jamesstroud.com