Inside Cover, Volume 34, Issue 9


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The image shows a snapshot taken from an AMOEBA molecular dynamics trajectory of a Cu(II) ion in water. The work by Jin Yu Xiang and Jay W. Ponder on page 739 describes a general molecular mechanics (MM) model for treating aqueous Cu(II) and Zn(II) ions based on valence bond (VB) theory and incorporated into the AMOEBA polarizable force field. Gas phase calculations of ion-aqua complexes show that the proposed AMOEBA-VB model improves the accuracy of MM model energetics for a number of ligation geometries when compared to results obtained by ab initio methods. Analyses of the molecular dynamics trajectories revealed a 6-coordination first solvation shell for both Cu(II) and Zn(II) ions in aqueous solution, with ligation geometries falling in the range reported by previous studies.