fix: change cif parser attribute name to construct Structure object

Author: stevenhua0320

src/diffpy/structure/parsers/p_cif.py

@@ -104,23 +104,23 @@ class P_cif(StructureParser):
             "_tr_atom_site_cartn_x",
             "_tr_atom_site_cartn_y",
             "_tr_atom_site_cartn_z",
-            "_tr_atom_site_U_iso_or_equiv",
-            "_tr_atom_site_B_iso_or_equiv",
+            "_tr_atom_site_u_iso_or_equiv",
+            "_tr_atom_site_b_iso_or_equiv",
             "_tr_atom_site_adp_type",
             "_tr_atom_site_thermal_displace_type",
             "_tr_atom_site_occupancy",
-            "_tr_atom_site_aniso_U_11",
-            "_tr_atom_site_aniso_U_22",
-            "_tr_atom_site_aniso_U_33",
-            "_tr_atom_site_aniso_U_12",
-            "_tr_atom_site_aniso_U_13",
-            "_tr_atom_site_aniso_U_23",
-            "_tr_atom_site_aniso_B_11",
-            "_tr_atom_site_aniso_B_22",
-            "_tr_atom_site_aniso_B_33",
-            "_tr_atom_site_aniso_B_12",
-            "_tr_atom_site_aniso_B_13",
-            "_tr_atom_site_aniso_B_23",
+            "_tr_atom_site_aniso_u_11",
+            "_tr_atom_site_aniso_u_22",
+            "_tr_atom_site_aniso_u_33",
+            "_tr_atom_site_aniso_u_12",
+            "_tr_atom_site_aniso_u_13",
+            "_tr_atom_site_aniso_u_23",
+            "_tr_atom_site_aniso_b_11",
+            "_tr_atom_site_aniso_b_22",
+            "_tr_atom_site_aniso_b_33",
+            "_tr_atom_site_aniso_b_12",
+            "_tr_atom_site_aniso_b_13",
+            "_tr_atom_site_aniso_b_23",
         )
     )
     # make _atom_setters case insensitive