Abstract
Our study is to develop a molecular simulation system that can predict the unknown structures of various compounds. As the first step, we have set up a precise crystal force field based on the Cambridge Structure Database (CSD). Since the modeling of force field including CH-π interaction was built previously, in this work, we have extended the current crystal force field with taking into account various hydrogen bonding interactions between CH groups, OH groups, NH groups to O,N atoms, respectively. Intermolecular potential functions are represented by the combination between the non-bonded interactions as buffered-14-7 function and hydrogen bond interactions as Modified Lippincot-Schroder (MLS) function. Parameters of buffered-14-7 functions are determined same as the MMFF94 optimal parameters, and parameters of MLS function are optimized by a parameter-optimization program (KGA). The crystal structures are optimized with the newly determined parameters of MLS intermolecular potential by nano-crystal structure optimization program (KESSHOU). Therefore, it's confirmed in this study that reasonably good reproducibility of the optimized crystal structures has been achieved.
