Green, Todd wrote: > Hello All, > > I have a question about some data with which I have been grappling. The > crystal appears to be primitive cubic(p23). Are there alternate ways to > index cubic data? I ask this question without regard to anomalous data.
For overall indexing, there are two ways in I23, I213, P23, P213 space groups. Imagine rotating crystal lattice by 90 degrees around a (or b or c) axis. The lattice is cubic, so it will overlap itself. But there is no fourfold axis in above space groups, so after 90 degree rotation, crystal content, and its diffracting pattern all be very different. I do not where this idea originated, but for anomalous data there is only one way of indexing them (unless you are Chang et all.) Zbyszek Otwinowski UT Southwestern Medical Center 5323 Harry Hines Blvd., Dallas, TX 75390-8816 (214) 645 6385 (phone) (214) 645 6353 (fax) [EMAIL PROTECTED]
