code: public void setMM2Parameters(IChemObjectBuilder builder) throws CDKException {
          try {
              if (mm2 == null) mm2 = new MM2BasedParameterSetReader();
              mm2.readParameterSets(builder);
          } catch (Exception ex1) {
              throw new CDKException("Problem within readParameterSets due to:" + ex1.toString(), ex1);
          }
          parameterSet = mm2.getParamterSet();
          atomTypes = mm2.getAtomTypes();
      }
docs: Sets the parameters attribute of the ForceFieldConfigurator object, default is mm2 force field