Solvent effect on the global and atomic DFT-based reactivity descriptors using the effective fragment potential model. Solvation of ammonia

The effective fragment potential (EFP) model has been used to study the effect of adding increasing numbers of the water molecules on several DFT-based reactivity descriptors of NH3. The HOMO-LUMO gap and electrophilic hardness are seen to increase with addition of water molecules; The importance on the wave function relaxation in the solvent effect on ammonia's properties is shown when analyzing the relaxation part in the electrophilic hardness and condensed Fukui function for the nitrogen atom. An increase in the atomic softness for the nitrogen atom with decreasing the global softness is observed. The saturation point for solvatation of ammonia was located around a cluster with 16 molecules of water. Atomic properties such as the Mulliken population, condensed Fukui function, and atomic softness for nitrogen and electrophilic global properties such as the hardness and its components for dilute solutions are predicted faithfully.