Obtaining example Silver Behenate data

• Zipped Example silver behenate data, XFIT and Celref files (Data collected by Tom Blanton) (133kB)

Fitting the Low Angle Asymmetric Peaks

• Run XFIT, select Load Data.

• Using the arrow mode combined with the the left and right mouse keys, Zoom up on the low angle area of interest to 17.7 degrees where the peaks are quite assymmetric.

• Select Ins/Del Peaks from the Options box.

• Select PVI (Split Pearson peak shape) from the Peak Edit Options box.

• Put the mouse over a peak and click left mouse button to insert a peak (right mouse button to remove a peak). Repeat this for the observed peaks.

  

• At this point we have to remember to define that this is Cu K alpha one and two data.

• Select File Details from the Options box. Select Assign LAMS to Files. Highlight the Assign Lam files option and click on the resulting Assign option to browse in the c:\koalarie directory for the cuka_2.lam file and select this.

  

• We should also allow the background to refine in a relatively flexible manner.

• Select Bkg Parameters from the Options box and insert a 5th order polynomial.

  

• Select Fit, Fit Marqartd to profile the peaks.

  

• While the raw data window is active, type s to unzoom. Go into arrow mode, zoom on the next area and repeat the sequence for the remaining asymmetric peaks (in this case up to around 23 degrees two-theta).

  

• for the remaining relatively symmetric peaks, select the PV (pseudo Voight) function; change the range and fit the remaining peaks.

  

• Select Fit, Fit Marqartd to profile the peaks.

  

• Now select File, Save Project to save all this information for later use.

• Then via the Options box, select File Details, Peaks (the bottom option), Two Theta All Pk Types. Select Create Text Report to get a Celref happy peak listing which can be save by closing the window (XFIT will prompt for a filename)