Re: global chi2

[Miguel Hesiquio Gardu?o]

Eli: Also you sjould check yor Rp and Rwp values, the chi^2 values could be hig due counting time, but you must model the background with a polinomial function. best regards Miguel Hesiquio ----- Original Message ----- From: eli To: [EMAIL PROTECTED] Sent: Thursday, August 26, 2004 3:54 AM Subject: global chi2 Dear Rietvelders I am trying to refine (fullprof) x-ray (Cu Ka) pattern of spinel CuTi2(S,Se)4 which was measured in flat specimen sample holder  in D8 Th:Th without monochromator (10-158 2Th). the experiment details were step each 0.02 2Th with 10 sec per step. the background was subtructed in EVA.  the problem that i am facing is that the R_Bragg is 3.71 but the global chi2 is 7.5 only if i am excluded the region to 10 - 80 2Th. what can be the reason for that?   Thank's in advance for your ideas   Eli