code: private void readNMRData(IChemModel model, String labelLine) throws CDKException {
          List<IAtomContainer> containers = ChemModelManipulator.getAllAtomContainers(model);
          if (containers.size() == 0) {
              // nothing to store the results into
              return;
          } // otherwise insert in the first AC
  
          IAtomContainer ac = containers.get(0);
          // Determine label for properties
          String label;
          if (labelLine.indexOf("Diamagnetic") >= 0) {
              label = "Diamagnetic Magnetic shielding (Isotropic)";
          } else if (labelLine.indexOf("Paramagnetic") >= 0) {
              label = "Paramagnetic Magnetic shielding (Isotropic)";
          } else {
              label = "Magnetic shielding (Isotropic)";
          }
          int atomIndex = 0;
          for (int i = 0; i < atomCount; ++i) {
              try {
                  String line = input.readLine().trim();
                  while (line.indexOf("Isotropic") < 0) {
                      if (line == null) {
                          return;
                      }
                      line = input.readLine().trim();
                  }
                  StringTokenizer st1 = new StringTokenizer(line);
  
                  // Find Isotropic label
                  while (st1.hasMoreTokens()) {
                      if (st1.nextToken().equals("Isotropic")) {
                          break;
                      }
                  }
  
                  // Find Isotropic value
                  while (st1.hasMoreTokens()) {
                      if (st1.nextToken().equals("=")) break;
                  }
                  double shielding = Double.valueOf(st1.nextToken()).doubleValue();
                  logger.info("Type of shielding: " + label);
                  ac.getAtom(atomIndex).setProperty(CDKConstants.ISOTROPIC_SHIELDING, new Double(shielding));
                  ++atomIndex;
              } catch (IOException | NumberFormatException exc) {
                  logger.debug("failed to read line from gaussian98 file where I expected one.");
              }
          }
      }
docs: Reads NMR nuclear shieldings.