Changeset 2807

Timestamp:

Apr 24, 2017 1:52:27 PM (6 years ago)

Author:

vondreele

Message:

fix offset problem in Bruker RAW powder importer
Some wordsmithing of the space group help text.

Location:

trunk

Files:

• GSASIIphsGUI.py (modified) (2 diffs)
• imports/G2pwd_BrukerRAW.py (modified) (1 diff)

trunk/GSASIIphsGUI.py

@@ -437 +437 @@
                 helptext = '''\t\t\tGSAS-II space group information
                 
-Space groups are entered here as given in Volume A of the International Tables,
-except that spaces are placed between operators (e.g. "P 4/m m m" or "P -3 1 m").
-
-Where a centrosymmetric space group has alternate origin settings, Origin 2 (with
-the center of symmetry at the origin, which gives a -x,-y,-z symmetry operator) is
-always used.
+Space groups are entered here as given in Volume I or Volume A of the
+International Tables using the short Hermann-Mauguin symbol,except that spaces
+are placed between axial fields (e.g. "P 4/m m m", "F D 3 M" or "p -3 1 m").
+NB: the cubic "bar" in "F d -3 m" is unnecessary, and upper/lower case is not required.
+
+Where a centrosymmetric tetragonal or cubic space group has alternate origin settings,
+Origin choice 2 (with the center of symmetry at the origin, which gives an -x,-y,-z 
+symmetry operator) is always used. Refer to the relevant pages in IT I or A to find
+the offset in atom positions between the two choices.
 
 For rhombohedral space groups, (R xxx) the hexagonal setting is assumed. Append a
 final R to the name (R xxx R) to indicate that a rhombohedral cell should be
-used (not recommended when alpha >> 120, due to correlation.)
+used (not recommended when alpha >> 120 or << 60, due to correlation.)
 
 GSAS-II will accept non-standard settings of space groups. For example, space
-group "P -1" can be set to include face centering, using symbol "F -1".
+group "P -1" can be set to include face centering, using symbol "F -1" and "P 1 1 21/a"
+as a nonstandard version of "P 21/c".
 
 Review the symmetry operators generated by GSAS-II to confirm that you have
 entered the right symbol for your structure.
 '''
-                dlg = G2G.SingleStringDialog(General,
-                                          'Get Space Group',
-                                          'Input the space group with spaces between operators (e.g. P 4/m m m)',
-                                          value=generalData['SGData']['SpGrp'],help=helptext)
+                dlg = G2G.SingleStringDialog(General,'Get Space Group',
+                    '  Input the space group with spaces between axial fields  \n  (e.g. p 21/c, P 63/m m c, P 4/m m m',
+                    value=generalData['SGData']['SpGrp'],help=helptext)
                 if not dlg.Show():
                     dlg.Destroy()
@@ -3526 +3529 @@
                     labelY='difference',newPlot=True,Title='DIFFaX vs GSASII',lines=True)
 #            GSASIIpath.IPyBreak()
-            G2plt.PlotPatterns(G2frame,plotType='PWDR')
+            G2plt.PlotPatterns(G2frame,plotType='PWDR',newPlot=True)
         else:   #selected area
             data['Layers']['Sadp'] = {}

trunk/imports/G2pwd_BrukerRAW.py

@@ -128 +128 @@
                 for iBlock in range(blockNum):
                     headLen = int(st.unpack('<i',File.read(4))[0])
-                    if nBlock > 1:
-                        headLen += 40
+#                    if nBlock > 1:
+#                        headLen += 40
                     nSteps = int(st.unpack('<i',File.read(4))[0])
                     if not nSteps: break