En las fronteras de la Materia Condensada

Gas-phase metal halides as KI are neutral molecules with low charge separation. On the other hand, fully solvated KI in the bulk phase experiences a total charge separation K⁺(sv)--I^-(sv). Some questions arises upon these facts. How is the relation between the number of molecules and the equilibrium distance K--I? Is this relation monotonous? In this work we study the structure and dipole moment of KI(H₂O)_n with n = 5, 10 and 42. Molecular dynamic simulations were performed with two different potentials: a hybrid QM-MM method and one based on classic potentials. We used a non-boltzmann umbrella sampling method in other to cover phase space regions which have a low probability to be visited for the system.