title: Distorted five-fold coordination of Cu2+(aq) from a Car-Parrinello molecular dynamics simulation.
abstract: The solvation shell structure and dynamics of a single Cu2+ ion in a periodic box with 32 water molecules under ambient conditions has been investigated using Car-Parrinello molecular dynamics simulations in a time-window of 18 ps. Five-fold coordination with four equidistant equatorial water molecules at 2.00 A and one axial water molecule at 2.45 A from the Cu2+ ion is found. A "hole" without water molecules is found on the opposite side of the axial water. The ion-water bonding character for the equatorial water molecules is different from that of the axial water molecules, as shown by a localized orbital analysis of the electronic structure. Moreover, the calculated OD stretching vibrational band for the equatorial water molecules lies ca. 175 cm-1 below the axial-water band, in good agreement with experimental data. The equatorial-water band lies below, and the axial-water band above, the pure liquid D2O band, also in agreement with experimental data.
authors.affiliation: Materials Chemistry, The Angström Laboratory, Uppsala University, Box 538, S-751 21, Uppsala, Sweden.
authors.forename: Sami
authors.initials: S
authors.lastname: Amira
authors.forename: Daniel
authors.initials: D
authors.lastname: Spångberg
authors.forename: Kersti
authors.initials: K
authors.lastname: Hermansson
mesh_terms: D000465:Algorithms; D002413:Cations, Divalent; D003198:Computer Simulation; D003300:Copper / Q000737:chemistry*; D017666:Deuterium Oxide / Q000737:chemistry; D008956:Models, Chemical; D010100:Oxygen / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D002413:Cations, Divalent; D014867:Water; D003300:Copper; D017666:Deuterium Oxide; D010100:Oxygen