GSAS Nickel example using EXPGUI (part 2)

2. Add a phase to the Experiment

The next step is to define a phase. EXPGUI will [now] only allow access to the Phase pane until a phase has been added with at least one atom. Switch to the Phase pane, and press the "Add Phase" button. Enter the appropriate information in the "add new phase" window and press the Add button.
Since a common source of errors is to improperly format the space group for GSAS, the generated operators are shown in a window. These should be checked. If you press Redo, you are given a chance to correct the space group.

Since the operators above are correct, press the Continue button and the phase is added and the output created from adding the phase is shown in a window. Press OK to continue. Press the "1" button that has just been added to the Phase pane to display the phase you have just entered.



(.EXP Snapshot at this point: nickel2.exp )

While the GSAS tutorial adds an atom to the phase later, in EXPGUI this is done now. If there were more than one phase, we would Select a phase by pressing the "1" button in the upper left. Then add an atom to the model by pressing the "Add New Atom" button in the lower right side of the Phase pane After entering the atom type, the coordinates added, and changing the Uiso value to match the example, press "Add" to add the atom to the .EXP file.

A box then optionally appears, as shown to the left, to show the results when the atom is read into EXPTOOL.


Note that the atom now appears on the phase page. Also note that the cell will not be refined, since the "Refine Cell" checkbutton in the upper right is not checked. Nor are any atomic parameters being refined, since X V and F do not appear in the ref./damp column.


Previous Step: Create a GSAS Experiment File
Next step: Add data (histograms) to the Experiment