The structure of Co2+ in liquid ammonia: Monte Carlo simulation including three-body correction

The solvation structure of Co2+ in liquid ammonia was investigated by the Monte Carlo simulation method. The simulation was carried out for a system containing one Co2+ and 215 NH3 molecules with ab initio generated pair and three-body corrected potentials, with the experimental density of pure liquid ammonia at 240 K and 1 atm. of 0.682 g cm−3, corresponding to a periodic cubic of side length 20.86 Å. The results prove the pair potential approximation to fail in predicting correct structural properties of the system. Consideration of the three-body effects reduces the first-shell solvation number of Co2+ in liquid ammonia from 8 to 6. The arrangement of ammonia ligands in the first solvation shell shows a rather distorted octahedron with average Co-N distance of 2.24 Å.