BUG: workaround for bug in pd.read_table

delim_whitespace=True does not work
pandas-dev/pandas#36381

Author: mcocdawc

src/chemcoord/cartesian_coordinates/_cartesian_class_io.py

@@ -161,7 +161,7 @@ def read_xyz(cls, buf, start_index=0, get_bonds=True,
         """
         frame = pd.read_table(buf, skiprows=2, comment='#',
                               nrows=nrows,
-                              delim_whitespace=True,
+                              sep='\s+',
                               names=['atom', 'x', 'y', 'z'], engine=engine)
 
         remove_digits = partial(re.sub, r'[0-9]+', '')