fix deepmodeling#359: read atom names from POTCAR if not present in O…

…UTCAR

dpdata/vasp/outcar.py

@@ -18,6 +18,14 @@ def system_info(lines, type_idx_zero=False):
                 atom_names.append(_ii.split("_")[0])
             else:
                 atom_names.append(_ii)
+        elif 'POTCAR' in ii:
+            # get atom names from POTCAR info, tested only for PAW_PBE ...
+            _ii=ii.split()[2]
+            if '_' in _ii:
+                # for case like : POTCAR:    PAW_PBE Ti_sv 26Sep2005
+                atom_names.append(_ii.split('_')[0])
+            else:
+                atom_names.append(_ii)
         # a stricker check for "NELM"; compatible with distingct formats in different versions(6 and older, newers_expect-to-work) of vasp
         elif nelm is None:
             m = re.search(r"NELM\s*=\s*(\d+)", ii)