docs: def properties(lines):
      """Parse properties block
  
      Returns:
          dict: {property_type: (atom_index, value)}
      """
      results = {}
      for i, line in enumerate(lines):
          type_ = line[3:6]
          if type_ not in ["CHG", "RAD", "ISO"]:
              continue  # Other properties are not supported yet
          count = int(line[6:9])
          results[type_] = []
          for j in range(count):
              idx = int(line[10 + j * 8: 13 + j * 8])
              val = int(line[14 + j * 8: 17 + j * 8])
              results[type_].append((idx, val))
      return results