Merge pull request #56 from easyScience/HM_ref_support

Added support for _space_group.name_H-M_ref keyword in CIF files

Author: sbillinge

src/diffpy/structure/parsers/p_cif.py

@@ -472,6 +472,7 @@ def _parse_space_group_symop_operation_xyz(self, block):
         sg_nameHall = (block.get('_space_group_name_Hall', '') or
                 block.get('_symmetry_space_group_name_Hall', ''))
         sg_nameHM = (block.get('_space_group_name_H-M_alt', '') or
+                block.get('_space_group_name_H-M_ref', '') or
                 block.get('_symmetry_space_group_name_H-M', ''))
         self.cif_sgname = (sg_nameHall or sg_nameHM or None)
         sgid = (block.get('_space_group_IT_number', '') or

src/diffpy/structure/tests/testdata/Ni_ref.cif

@@ -0,0 +1,21 @@
+data_2102245
+_cell_length_a 3.562
+_cell_length_b 3.562
+_cell_length_c 3.562
+_cell_angle_alpha 90.00000000
+_cell_angle_beta 90.00000000
+_cell_angle_gamma 90.00000000
+_space_group_name_H-M_ref 'F m -3 m'
+
+
+loop_
+_atom_site_label
+_atom_site_type_symbol
+_atom_site_fract_x
+_atom_site_fract_y
+_atom_site_fract_z
+_atom_site_occupancy
+_atom_site_adp_type
+_atom_site_U_iso_or_equiv
+Ni Ni 0.00000000 0.00000000 0.00000000 1.00000000 Uiso 0.025
+

src/diffpy/structure/tests/testp_cif.py

@@ -71,6 +71,7 @@ class TestP_cif(unittest.TestCase):
     graphiteciffile = datafile('graphite.cif')
     cdsebulkpdffitfile = datafile('CdSe_bulk.stru')
     teiciffile = datafile('TeI.cif')
+    refciffile = datafile('Ni_ref.cif')
     places = 6
 
 
@@ -334,6 +335,14 @@ def test_spacegroup_anisotropy(self):
         self.assertTrue(all(stru.anisotropy))
         return
 
+    def test_spacegroup_ref(self):
+        "verify space group reference"
+        pfile = self.pfile
+        pfile.parseFile(self.refciffile)
+        sg = pfile.spacegroup
+        self.assertEqual('Fm-3m', sg.short_name)
+
+        return
 
     def test_adp_type_ani(self):
         "verify adp type override to anisotropic"