Hello everyone,
Has anyone else noticed that sometimes when comparing two models Rwp is better for one and R(F^2) is better for the other? The case I am looking at is spacegroups P3 versus P-3, with the non-centrosymmetric structure having more degrees of freedom and therefore very slightly better Rwp (7.6% versus 7.7%). I don't understand why it has a much worse R(F^2), 8.5% versus 7.3%. These numbers are coming from GSAS, which gives the same number of F_obs reflections for each of the two fits. I haven't looked into the details much, but shouldn't the two statistics be better correlated than that?
Thanks for any hints!
Jon
