Inclusion of the Most Important Multi-Particle Interactions in the AMBER Force Field and Optimization of Energy Parameters of the Revised Force Field
Garbuzynskiy S.A., Matkarimov B.T., Finkelstein A.V.
Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290 Russia
National Laboratory Astana, Nazarbayev University, Astana, Kazakhstan
Abstract. A new functional form for force field of non-covalent interactions is developed. Besides traditional members, it involves induced (by partial charges) polarization of all atoms as well as three-particle dispersion interactions of atoms with covalent bonds. The corresponding new members are added to a standard AMBER force field. Within this unified functional form of the force field, parameters of all types of non-covalent interactions are optimized using data on molecular crystals. A noticeable increase in correlation coefficient between calculated and experimental energy of cohesion of molecules in molecular crystals is shown.
Key words: non-covalent atom-atom interactions, three-particle interactions, polarizability, partial charges, “atom-covalent bond” interaction, molecular crystals, energy of cohesion.