Classical and QM/MM molecular dynamics simulations of Co2+ in water

• DOI: 10.1016/j.chemphys.2003.08.006
• Publication Date: 2003-10-09T03:38:24Z
• Authors: Ria Armunanto; Christian F Schwenk; A.H Bambang Setiaji; Bernd M Rode
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract Classical and quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) simulations have been performed to describe structural and dynamical properties of Co2+ in water. The most important region, the first hydration shell, was treated by ab initio quantum mechanics at unrestricted Hartree–Fock (UHF) level using the LANL2DZ ECP basis set for Co2+ and the double-ζ plus polarization basis set for water. For the rest of the system newly constructed three-body corrected potential functions were used. A well-structured rigid octahedron was observed for the stable first hydration shell showing no first shell water exchange process within a simulation time of 11.9 ps. For second hydration shell ligands, a mean residence time of 28 ps was observed. Librational and vibrational motions as well as the ion–oxygen motion were investigated by means of velocity autocorrelation functions showing significant differences between classical and QM/MM results.