code: def read_cs_core_contribution(self):
          
          header_pattern = r'^\s+Core NMR properties\s*$\n' \
                           r'\n' \
                           r'^\s+typ\s+El\s+Core shift \(ppm\)\s*$\n' \
                           r'^\s+-{20,}$\n'
          row_pattern = r'\d+\s+(?P<element>[A-Z][a-z]?\w?)\s+(?P<shift>[-]?\d+\.\d+)'
          footer_pattern = r'\s+-{20,}\s*$'
          self.read_table_pattern(header_pattern, row_pattern, footer_pattern, postprocess=str,
                                  last_one_only=True, attribute_name="cs_core_contribution")
          core_contrib = {d['element']: float(d['shift'])
                          for d in self.data["cs_core_contribution"]}
          self.data["cs_core_contribution"] = core_contrib
docs: Parse the core contribution of NMR chemical shielding.
  
              Returns:
              G0 contribution matrix as list of list.