Development of New Force Field and Evaluation of Conformational Energy

Abstract

Molecular simulations using conventional force fields have been successful for understanding the nanoscopic behavior of molecules in several chemical environments. However, the classical approaches have some shortcomings due to the electrostatic interaction calculated by fixed atomic charges. To describe the charge reorganization due to nuclear structrural changes of the molecules, we developed the new charge equilibration (NQEq) framework and introduced it into molecular force field MMFF94s. For reproducing the relative energies of conformational isomers of the organic compounds obtained by MP4(SDQ) level, we refined the parameter set of torsion interaction term. The new force field, named MMFF/NQEq, can reproduce the conformational energies better than those by MMFF94s.