New parameterization of the PM3 method for monosaccharides

We derived new parameters for the semi-empirical PM3 method, PM 3 MS , designed for studies of saccharides. The parameters were optimized using genetic algorithm procedure. We used the MP2/cc-pVTZ energies and optimized geometries of monosaccharides as the reference set. Results show that compared to the standard PM3, the new PM 3 MS parameters predict better ordering of the conformers energy both for the members of the training set, as well as those outside the training set.